Regular composting, also known as cold composting, involves placing a variety of organic materials in a compost bin, enclosure, or even just in a large heap, and leaving it there until it breaks down several months later. It’s a very slow process and typically takes 6 to 12 months. It can be sped up by turning the compost, that is, moving around the material at the bottom of the heap to the top and vice versa to mix it up and get more oxygen in there, but it’s still a long wait. But there’s a better way to do composting…
The Difference Between Hot and Cold Composting
The other approach to composting is hot composting, which produces compost in a much shorter time. It will effectively destroy disease pathogens (such as powdery mildew on pumpkin leaves), weed seeds, weed roots (such as couch and kikuyu) and weeds which reproduce through root bulbs (such as oxalis). This process breaks down the material much better to produce a very fine compost.
By comparison, the slower cold composting methods will NOT kill disease pathogens or weed seeds and roots, so if this compost is put into the garden it may spread weeds and plant diseases, hence the common advice not to (cold) compost diseased plants.
The other issue with cold composting is that it produces a coarser compost, with lots of large pieces of the original materials left over in the compost when the process is completed, whereas hot compost looks like fine black humus (soil), and none of the original materials are distinguishable.
Hot composting is a fast aerobic process (uses oxygen), so given volume of compost materials produce almost the same volume of finished compost. In contrast, cold composting is slow anaerobic process (without oxygen), it’s a different chemical process, and as a result, nitrogen and carbon are lost to the atmosphere, which causes a reduction in the volume of compost to 20% of the original volume.
The Berkeley Hot Composting Method
The hot composting method, known as the Berkeley method, developed by the University of California, Berkley, is a fast, efficient, high-temperature, composting technique which will produce high quality compost in only 18 days.
The requirements for hot composting using the Berkley method are as follows:
- Compost temperature is maintained between 55-65 °C (131-149 °F)
- The C:N (carbon:nitrogen) balance in the composting materials is approximately 25-30:1
- The compost heap needs to be 1m x 1m (3′ x 3′) wide and roughly 1.5m (5′) high
- If composting material is high in carbon, such as tree branches, they need to be broken up, with a mulcher for example
- Compost is turned from outside to inside and vice versa to mix it thoroughly
With the 18-day Berkley method, the procedure is quite straightforward and can be summarised into three basic steps:
- Build compost heap
- 4days – no turning
- Then turn every 2nd day for 14 days
Detailed, step -by-step instructions of the Berkeley hot composting method are provided later in this article, but before we can begin composting , we need to get the right mix of materials into our compost!
Getting the Best Composting Material Carbon-Nitrogen Balance
In all composting, including the Berkeley hot composting method, the ratio of carbon to nitrogen in the compost materials needs to be between 25 to 30 parts carbon to one-part nitrogen by weight. This is because the bacteria responsible for the composting process require these two elements in those proportions to use as nutrients to construct their bodies as they grow, reproduce and multiply.
Materials that are high in carbon are typically dry, “brown” materials, such as sawdust, cardboard, dried leaves, straw, branches and other woody or fibrous materials that rot down very slowly.
Materials that are high in nitrogen are typically moist, “green” materials, such as lawn/grass clippings, fruit and vegetable scraps, animal manure and green leafy materials that rot down very quickly.
Many composting ingredients don’t have the ideal carbon to nitrogen ratio of 25-30:1. To make composting work, we get around this problem by mixing high carbon materials which break down very slowly, with high nitrogen materials which decompose very quickly, in order to create the right balance.
The nitrogen content of composting materials is denoted by the carbon to nitrogen ratio (C:N ratio) assigned to them, as detailed in the tables in the next section. Before we examine those, let’s have look some quick examples to understand how C:N ratios work..
- Materials high in nitrogen, which decompose very quickly, such as fish, which have a C:N ratio of 7:1, have a very low C:N ratio .
- Materials low in nitrogen, which break down very slowly, and need to be broken up to be used, such as tree branches, which have a C:N ratio of of 500:1, have a very high C:N ratio
The rationale for mixing ingredients is as follows.
If the C:N ratio in our composting materials is too high, meaning we don’t have enough nitrogen and too much carbon, we can lower the C:N ratio by adding manure or grass clippings, which are high in nitrogen.
If the C:N ratio in our composting materials is too low, meaning we have too much nitrogen, we you can raise the C:N ratio by adding cardboard, dry leaves, sawdust or wood chips, which are high in carbon.
When trying to understand C:N ratios, it may helpful to point out that all plants have more carbon than nitrogen in them (remember, they get their carbon from the carbon dioxide in the air) so that’s why the C:N ratios of plant material is always greater than 20:1.
Below are the average C:N ratios for some common organic materials used for composting
Carbon-Nitrogen (C:N) Ratios of Common Composting Materials
Here is a handy list of composting materials with their respective carbon to nitrogen, or C:N ratios.
The materials at the top of the list contain higher amounts of carbon, but are low in nitrogen, and are considered ‘browns‘.
As we move down the list, the nitrogen content increases, and the materials at the bottom of the list contain higher amounts of nitrogen, and are considered ‘greens‘.
| Browns = High Carbon | C:N |
| Wood chips | 400:1 |
| Cardboard, shredded | 350:1 |
| Sawdust | 325:1 |
| Newspaper, shredded | 175:1 |
| Pine needles | 80:1 |
| Corn stalks | 75:1 |
| Straw | 75:1 |
| Leaves | 60:1 |
| Fruit waste | 35:1 |
| Peanut shells | 35:1 |
| Ashes, wood | 25:1 |
| Greens = High Nitrogen | C:N |
| Garden waste | 30:1 |
| Weeds | 30:1 |
| Green Wood | 25:1 |
| Hay | 25:1 |
| Vegetable scraps | 25:1 |
| Clover | 23:1 |
| Coffee grounds | 20:1 |
| Food waste | 20:1 |
| Grass clippings | 20:1 |
| Seaweed | 19:1 |
| Horse Manure | 18:1 |
| Cow Manure | 16:1 |
| Alfalfa | 12:1 |
| Chicken Manure | 12:1 |
| Pigeon Manure | 10:1 |
| Fish | 7:1 |
| Urine | 1:1 |
What Materials Can Be Composted?
Anything that was once living can be hot composted – and I really do mean anything. All manner of things, including unusual items such as wool and cotton clothing, bones, leather boots (with leather soles).
Some farmers who use the hot compost method even place a fresh animal roadkill into their hot compost heaps (they have to go in the very centre of the hot compost heap to break down properly) because they are a high nitrogen source, and they find nothing but clean bones when the compost is ready. Not a good idea for urban areas though!
It’s best to use a variety of different ingredients in the compost, as this provides an input of a wider range of nutrients, and produces a richer compost.
There are many organic materials that can be composted, and there are also certain ingredients that should never be put into a compost bin. This is subject is a whole article in itself, so if you want more information, here is a link to a list of what materials should and shouldn’t go into your compost bin.
The Easiest Way to Mix Compost Materials for the Right C:N Ratio
Some gardeners are perfectionists and try to use some very complex mathematics to calculate the exact proportions of each ingredient they’re using to arrive at the ideal C:N ration of 25-30:1 by weight. This is totally unnecessary, and there’s a very simple alternative that works great, which is a measure by volume.
The One Bucket Greens, Two Buckets Browns Method
If ratios seem too complicated or confusing (which they are), you can work with volumes of ingredients instead to simplify things.
- Use 1/3 ‘greens’ (nitrogen containing) materials with 2/3 ‘browns’ (dry carbon materials).
Or to put it another way, which may be easier to understand:
- Add one bucket of nitrogen-rich material to every two buckets of dry carbon-containing material.
For example, using this method we could use 1/3 Manure and 2/3 dry carbon materials to start a hot compost pile and it will work. Alternating thin layers of greens and browns are laid down until the compost heap is 1 metre (3 foot) square and a bit taller than that.
There’s no real need to get caught up in the mathematics of precise C:N ratios for succesful hot composting. It’s more a matter of trying out the process by following the instructions below, and it really is quite easy.
Hot Composting in 18 Days, Step By Step Instructions
The following instruction detail the steps required to build a Berkeley hot composting system which will produce finished compost in around 18 days.
DAY 1 – Construct Compost Pile, Let it Sit for 4 days
- Mix together ingredients by laying then in alternating thin layers of “greens” and “browns”.
- Wet the compost heap down very well so it is dripping water out of the bottom and is saturated.
- Let the compost pile sit for 4 days (this day and three more days), don’t turn it.
- Tip: A compost activator such as comfrey, nettle or yarrow plants, animal or fish material, urine, or old compost, can be placed in the middle of compost heap to start off composting process.
DAY 5 – Turn Compost Pile, Let it Sit for a Day
- Turn the compost heap over, turning the outside to the inside, and the inside to the outside. To explain how to do this, when turning the compost, move the outside of the pile to a spot next to it, and keep moving material from the outside to the new pile. When the turning is completed, all the material that was inside the pile will be outside and vice versa.
- Ensure that moisture stays constant. To test, put gloves on and squeeze a handful of the compost materials, which should only release one drop of water, or almost drips a drop.
- On the next day, let the compost pile sit, don’t turn it.
- TIP: If the compost pile gets too wet, spread it down, or open a hole about 7-10cm (3-4”) wide with the handle of the pitchfork, or put sticks underneath for drainage.
DAY 7 & DAY 9 – Measure Temperature, Turn Compost, Let it Sit for a Day
- Measure the temperature at the core of the compost heap.The compost heap should reach its maximum temperature on these days. As an simple guideline, if a person can put their arm into the compost up to the elbow, then it is not at 50 degrees Celsius, and is not hot enough. Best to use a compost thermometer or a cake thermometer for this purpose.The hot composting process needs to reach an optimum temperature of 55-65 °C (131-149 °F).At temperatures over 65 °C (149 °F), a white “mould” spreads through the compost, which is actually some kind of anaerobic thermophilic composting bacteria, often incorrectly referred to as ‘fire blight’. This bacteria appears when the compost gets too hot, over 65 °C and short of oxygen, and it disappears when the temperature drops and aerobic composting bacteria take over once again.Temperature peaks at 6-8 days and gradually cools down by day 18.
- Turn the compost heap over every second day (on day 7 and again on day 9).
- Allow the compost to rest for on the next day after turning it.
- TIP: If the compost pile starts coming down in size quickly, there is too much nitrogen in the compost.
- TIP: To heat up the compost faster, a handful of blood & bone fertiliser per pitchfork when turning speeds it up.
- TIP: If it gets too hot and smelly and goes down in size, it has too much nitrogen, need to slow it down, throw in a handful of sawdust per pitchfork when turning.
.
DAY 11, 13, 15 and 17 – Turn Compost, Let it Sit for a Day
- Continue to turn the compost every 2nd day (on days 11, 13, 15 and again on day 17).
- Allow the compost to rest for a day after turning it.
DAY 18 – Compost Completed, Ready to Harvest
- Harvest completed compost, which will be warm, dark brown, and smell good.
- Congratulate yourself for a job well done!
- TIP: When the earthworms move into the compost, it’s a sign that it’s finished and ready, because it’s cooled down enough for them and they’re in there because it’s full of nutrients!
Some important points to note:
- Locate the compost heap in an area which is protected from too much sun to prevent the compost from drying out, or from heavy rain to avoid water-logging, as both extreme conditions will slow down the composting process.
- Space required for for your heap should be about 1.5 x 1.5 metres (5′ x 5′), and enough space in front of it to stand when turning the compost.
- Water each layer until it is moist as you build the heap. After three or four days, give the compost air by mixing and turning it over, then turn every two days until the compost is ready, usually in 14-21 days. Remember, frequent turning and aeration is the secret of successful composting.
- Turn the compost using a garden fork, or even better, a long-handled pitchfork.
- In cold or wet weather, cover the compost heap with a tarp or plastic sheet, to prevent the rain cooling it down, since the water will penetrate into the core of the compost pile. Even though cold outside air will cool the surface, but not the core of the compost heap, by covering it, this prevents some heat loss from the surface to cooler outside air, and retains the heat within the compost heap better.
Is My Garden Too Small for Hot Composting?
A full–sized hot compost pile can be made successfully in a small courtyard, I know from experience!
The first time I tried hot composting was assisting a friend with only a small courtyard in a rental property, who had never tried this process before. For composting materials, he gathered a wheelie bin full of fallen leaves from his local street, a second wheelie bin full of weeds from his garden, and he also purchased a small straw bale for the sake of it. I also helped him collect a few garbage bags of cow manure from an urban farm. It took us under an hour to pile up all the materials in reasonably thin layers of less than 5cm (2″) to build the compost heap.
Even though it was his first attempt at hot composting, and in around 18 days, he had over 1 cubic metre of rich, dark, compost to use in his garden. None of the original ingredients could be identified in the final product either, it had a very fine consistency. Best of all, it cost him next to nothing – the straw bale was the only item purchased, and that was more of a gratuitous addition, as the hot compost would have worked just as well without it.
Considering that a hot compost pile doesn’t really reduce in volume, the biggest issue in small yards and gardens is figuring out what to do with such a large volume of high-quality compost!
Ways to Use Compost in the Garden
Wondering what to do with over a cubic metre of freshly made compost?
- It can be used to improve your soil by digging it through your garden beds.
- Don’t like digging? Use the compost to start a no-dig garden with the no-dig gardening method, which is my personal preference!
- Compost should be always mixed into the soil to improve drainage in heavy clay soils, and to improve water retention in sandy soils when planting new trees.
These are just a few ideas to get things started. Happy composting!
Beautifully & clearly explained . Thank you. Methinks you ought to be a teacher.
Of anything at all ! I suspect you love the process ? Especially PERMACULTURE .
[ I visited your back yard once with the NERP PERMIE mob. Most impressive, as we all said on the day. I have meant to say previously : YOUR concern about the lead sheet flashing around the chimney is misplaced – with all due respect. I guarantee that you could not detect a DIFFERENCE between water from the East face of the house and the west face. Consequently I suggest that NOT collecting all that water ‘cos of the lead sheet flashing is a waste. { I also heard that there was a second reason for NOT collecting same ! } ] Warm regards david hicks…..Eltham N.
Thanks David,
Appreciate the supportive feedback. You’ve got it right, I do have a passion for training/teaching, trying to do a career change into this area! Would love to teach permaculture!
Thanks for the advice on the lead flashing, it’s quite common on a lot of old buildings as you know, and it is a concern for quite a few people. I seriously haven’t looked to deeply into the matter, namely because my tanks can only hold the water I capture from the garage roof (30 sq. m), don’t have capacity for the rest, that would come at a later date. There are a few other minor technicalities too, which I won’t burden you with.
I’m currently working on a food garden community project, and they’re also avoiding capturing water off a slate tile roof with lead flashing. There’s so much water there to be had…
I agree, it is a terrible waste not to capture the water. I would love to be able to do the testing or find some research on the matter, because it’s very common for people to err on the side of caution, and not capture water in these situations.
You’ve motivated me to go do some research and find some scientific research papers on this, because if you’re right on this, and I don’t have reason to doubt what you say, this will give immense reassurance to people in this situation, and increase the amount of water captured for productive use, rather than flow down the stormwater drain.
You’ll most likely see an article on this soon if my seearch goes well, thanks for inspiring me to look into this!
Regards
Dear Sir/Madam
I really like this simple composting system. i’m trying my best to do in your simple explained way . Thank you so much.
Regards.
I too am enjoying this, and have used your guide to process my second lot!
Urine, coffee CHAFF, water, witch’s hat composter, Boston, MA–winter
Hi, I’m wondering if anyone on this list could help me with the ratios, etc. for this project? Would I be better off sealing it into a barrel with holes and rolling the barrel around, like those big composting spheres? The idea behind the witch’s hat composter is that the inner hole filled hat aerates the pile, the top hat covers it and exerts some downward pressure (it’s surrounded by a 4 ft tall perimeter of plastic). Thanks.
What I understand of this process is that it needs to have a minimum volume to attain the ideal temperature. That seems to be close to 1 cubic meter, a little more than a cubic yard or 30 cubic feet. If smaller the core would not attain the temperature of 55-65’C 130-150’F. Multiply this by ten and you have enough heat for your house for a season. The article says 1.5m (5ft) high pile, which as a pyramid comes to about 1 cu.m If your pile becomes too big with the right composition you have to monitor the heat at the core and turn it if it exceeds the high temperature limit. It does work if you can get a huge barrel. You may have a hard time rolling it as it probably weighs about a ton and a half (barrel and contents). That’s as much weight as an old Lincoln 🙂
This whole method I believe was devised by Jean Pain in France who unfortunately died too young, but wrote a book about it. It is called the Jean Pain compost method, not the Berkeley method. Pain’s goal was not to produce good compost but to extract heat and energy out of the composting process. He heated water pipes and collected methane.
Here is a link and the book itself that has been out of print
permaculturenews.org/2011/12/15/the-jean-pain-way/
files.uniteddiversity.com/Permaculture/Another_Kind_of_Garden-The_Methods_of_Jean_Pain.pdf
Geoff Lawton mentions this in his movie “Soils” and he is one of the forefathers of permaculture and my favorite advocate. The reason he is my favorite is that he presents the subject in a way that emphasizes that this can not possibly be perceived as “individual practice and solution”, but a collective-communal paradigm shift for humanity to become what it really is, on point in this huge cycle of life and coexistence – sustainability. “It is the only hope we have”, he says, as a specie.
For making compost, and lots of it, it’s the Berkley method! 🙂
The volume given of one cubic metre is a minimum, there is no maximum size, some farmers turn piles that are much higher and many metres long with a front-end loader. The 1.5m pile is not really a pyramid, more a rectangular mound with a wider base, which is over 1 cubic metre in volume.
Yes, Geoff Lawton (my teacher along with Bill Mollison) explains technical material brilliantly and he explains it in terms of systems that work together. No man is an island, we all achieve more when we work together as a community.
I also workfort a community food garden (it supplies a food pantry for the needy) and also helped with the redesign of another community garden that is about 1/4 acre. That second garden had an IBC water tank but it was attached to nothing… and a shed in another area. With the redesign they are now getting all the water they need by collecting water from both sides of the shed. My point is, even small sheds can collect quite a bit of water. If your building won’t work, could you get a small (10′ x 12′) shed and collect water from it instead of the building with lead flashing?
Do you know how bamboo would be calculated in this?
Dry bamboo, fresh bamboo? It depends. Dry bamboo would have the same C:N ratio as wood chips, and fresh bamboo would have the same C:N ratio as garden waste, because they’re essentially the same materials.
I would use both. I was curious because Bamboo is considered in the same family as grass so it’s interesting. I have a lot of both dry and fresh.
Hi. I enjoyed reading your website, it’s very well put together. Just one thing I would say is not correct in my experience as organic gardener and educator. A cold heap is not necessarily, or at least shouldn’t be, anaerobic. It still needs aeration and with the right balance of carbon and nitrogen and regular turning it would prevent this from happening. An anaerobic cold heap would smell, probably isn’t looked after and possibly contains too much nitrogen rich materials like grass clippings. It attracts the kind of bacteria you don’t want in the garden and is not considered to be a good approach..
Thanks for the great feedback! Perhaps I should express myself point better when discussing cold composting. Cold composting only turns anaerobic when it goes terribly wrong! Both hot and cold composting are aerobic processes, the former is just a lot faster than the latter. When both types of compost are are turned regularly, they become aerated, which promotes breakdown of the materials, and production of compost.
Hi Angelo,
I’m loving your website, thanks mate.
This thread spurred me to research. Lead in tankwater is a real consideration, this from a CSIRO study: “The rainwater collected from all three roofs with lead flashing contained Pb concentrations exceeding the ADWG (and WHO) maximum recommended values”
http://www.csiro.au/files/files/pk7r.pdf
I’ve had it recommended by someone to put lime and/or shells into the tank so the water turns alkaline and lead precipitates out of solution. This paper looks like it’s saying that’s not an effective strategy…
http://md1.csa.com/partners/viewrecord.php?requester=gs&collection=ENV&recid=8102070&q=&uid=790086948&setcookie=yes
Quote: “an increase in carbonate promotes formation of more soluble lead carbonate complexes.”
There are effective water filters for drinking. Not much use for the garden.
Can you really make a compost without it shrinking? I’ve never done that. I think they produce a lot of carbon dioxide as the microbes metabolise, so you have to lose some mass. And the whole thing settles too so loses some extra volume. That’s my experience anyway.
I’d love to teach a permaculture course with you someday!
Adam
Hi Adam,
Thanks, really appreciate the links to the lead in tankwater research, I was looking for this information as it’s a topic of concern for many people who wish to harvest rainwater from their rooftops, lead flashings unfortunately are quite commonly used on Australian rooftops.
With hot (aerobic) composting, you’re right, the process of aerobic decomposition will oxidise carbon and create cabon dioxide, the amount of carbon is reduced as all the available nitrogen is utilised and captured. The reduction will be ever so small if you have an abundance of carbon rich materials so nitrogen is not lost. If the compost heap is compacting down too much, you need to add more carbon-rich materials. Agreed, the volume will also reduce slightly due to the physical breakdown and subsequent compaction of the composting materials too. You’ll lose some volume, but nothing drastic, my guess is you’ll definitely always have well over 50% of original volume, possibly closer to 75%. It’s hard to estimate accurately because I’ve never measured the volume accurately, so my estimates are somewhat subjective. Compare this with slow anaerobic composting, where the you will only end up with 20% of the original volume, you lose around 80% of volume, that’s quite a difference! It’s quite disappointing with slow (anaerobic) composting to fill a 200L compost bin and end up with only 40L of compost, but it’s still something…
Love your work too, would most welcome the opportunity to teach a permaculture course together!
Regards
Adam, it’s pretty easy to design a water collection system to have a “first flush” feature to it. The first rain that comes would take the majority of the pollutants (like lead from the flashing) with it, and then the remainder would be much cleaner, and can be sent through a filtering system to remove what remains. This really isn’t as hard as it sounds. There are a number of options for designs so I won’t go into detail, but usually I come across designs on YouTube or at off-grid living websites (where they are needing to use the rainwater for drinking water).
Hi, awesome site. Can you explain how to keep the temperature of the compost at 55-60 Celsius? I’m guessing you put it under a heat lamp?
Hi Jason, thanks for your comment. There is no need for an external heat source at all, the bacteria in the compost heap generate the heat by themselves! They can generate so much heat that haystacks on farms which have gotten damp in the centre and have started composting can actually burst into flames! Luckily that won’t happen with the compost. The bacteria consume the compost heap as they multiply, and when they chemically break down the organic matter into simpler compounds, heat is released. This encourages the heat loving bacteria, which break down the compost even further. That’s the magic of hot composting!
Wow, that really is amazing. Thank You for the info!!
I have often wondered how the bacteria release heat, and i’m guessing it is by breaking chemical bonds with their digestive process, but i know nothing more. Do you know anything more about this? Does it have to do with nitrogen being turned into nitrates?
Jason, I use a long probe thermometer inserted into the center of the pile. When it reaches 150 I turn the pile. I use shredded leaves and chopped alfalfa. A lawnmower works just fine for this.
Hi there. Great instructions! The only thing is, I’m based on the West Coast of Ireland. Its summer now and the weather is blustery and cool with sporadic sunshine. Will this quick composting system still work here or does the outside air temp affect how the bacteria generate heat? ie: will this weather slow down the process? I am a permaculture student and everyone who has passed on their knowledge of hot composting systems here in Ireland say it will be ready at the earliest 6-8 weeks after constructing. Do you have any thoughts or tips on this?
Thank you! Julie
Hi Julie,
I didn’t realise Irish summers are so cool (cold)!
The hot composting process is driven by the bacteria, they generate the heat through the decomposition of the organic matter in the compost heap.
The compost heap is normally covered with a tarp or plastic sheet, to prevent the rain cooling it down, since the water penetrates into the core of the compost pile.
Cold outside air will cool the surface, but not the core of the compost heap. The covering prevents some heat loss from the surface to cooler outside air, and retain the heat within the compost heap better.
I must confess, I can produce compost in my tumble bin in 6-8 weeks in winter here. It only holds 200 litres, not enough for the hot composting process, and it only gets warm.
I’m pretty sure a hot composting pile should still work in 18 days in even a cool summer.
Ok, here’s a few tips to keep that hot compost pile running hot in cooler weather:
1. Make the pile as big as you can, bigger compost heaps retain heat better than smaller ones.
2. Increase the amount of nitrogen sources (greens) in the compost
3. Add some very ‘hot’ sources of nitrogen, such as horse manure, chicken manure or coffee grounds
4. Insulate the compost heap to retain the heat – cover it with a black plastic tarp (not airtight though, it needs a good supply of oxygen) or any other insulating material, get creative!
5. Place your compost in a location where it is protected from the wind.
6. Situate the compost heap in a position where it receives full sunlight (north in the southern hemisphere, south in the northern hemisphere)
Im curious to know how well it works in a cold Irish summer!
Regards
How do you manage to get cold/cool compost finished in 6 weeks?
I’ve been tumblimg mine for 2 months and isn’t even halfway there.
Do you use a similar C/N ratio as per hot composting and have you any tips for those of us who struggle to find space even for a 200l tumber and have no chance of building a big hot compost pile.
Very nicely written article btw
Gerry C
Thanks Gerry, the trick to getting cold composting in 6 weeks is as follows:
1. Processing – Feed all materials through a mulcher first, the finer the compost materials are, the faster they break down. I think this makes a huge difference. Otherwise, just chop materials quite fine with a garden spade on the ground (not in the soil, it will compact it!), or using secateurs or hedge clippers to chop everything up first while the materials are sitting in a large container.
2. Temperature – composting slows down in the cold weather, placing the compost tumbler in a warm spot speeds things up, and the 6 week turnover only happens during the warmer seasons for that reason.
3. Materials – use materials that break down relatively quickly, and use a good mix of materials. For carbon containing materials, pea sraw, lucerne, dried grasses, newspaper break down faster than heavy branches that are mulched and still consist of large, chunky pieces. Add lots of nitrogenous (green) material, this breaks down very fast. Ratios of carbon to nitrogen are the least critical in a compost tumbler, technically you could compost green grass clippings alone as long as you turn it daily, but it’s best to add a good mix of mterials to try to achieve the optimum C:N ratio. With too much excess nitrogen, you lose to much of the nitrogen from the compost to the air because there is not enough carbon to bind it.
4. Volume – try to get as much materials as possible to fill the compost tumber in one go, it will heat up a bit on its own, but not enough to make it a hot compost, so it’s still cold composting.
Ah, thanks a million for your speedy response – much appreciated. Will definitely use onsite horse manure to help heat pile. We also have sheep manure mixed with straw that I am hoping to use. Just wondering what your thoughts are on using bracken as a green? We have an abundance of. Some people seem to think that it doesn’t break down properly. I was also thinking of using it for capping the heap as an insulator under the black plastic.
Also I have often been told that having a particle size of 2.5cm3 is optimum – is this neccessary for such a quick system?
Will keep you updated as to the results of our test!
Thanks again, Julie
Hi Julie,
No, there’s no real need to break up the material into very small pieces when hot composting, the combination of heat and bacterial activity can break doen a lot of things that would surprise a lot of people. – materials added to the centre of hot compost piles that have broken down completely include such things as leather boots, woolen jumpers, and roadkill (dead animals). With the latter only clean bones are left behind. Breaking things up roughly is usually sufficeint. 2.5cm3 or one cubic inch is the particle size you get from a chipper (a coarse mulcher), which is what I use for cold composting. Chopping up the material finely increases the exposed areas in the material that bacteria can act on, naturally speeding up the process of breakdown and decomposition. It definitely always helps but is not critical in hot composting.
Also, bracken ferns can be hot composted. Normally they are allelopathic, that is, they release chemicals which prevent other plants from growing, but thankfully the hot composting destroys these substances. Bracken ferns are a good source of potassium and break down slowly to create an acidic compost.
The Royal Horticiltural Society mentions using Bracken Ferns as a compost, see http://apps.rhs.org.uk/advicesearch/profile.aspx?pid=445#section5
Here’s a brief extract from the RHS article:
Bracken ferns are believed to be carcinogenic, the current opinion is that people working extensively with them are at an slightly increased risk so try not to breathe the spores when working with them, a face mask might be a good idea.
Regards
Ah great! Thanks for that!
So we are on day 11 of our hot composting in a cold climate experiment. We turned it again yesterday and it is still quite hot – 55-60 degrees in places. On the first few turns there was evidence of slight white mould but only on bracken in the heap. We added shredded newspaper to counteract.
So yesterday, on day 10 turning, we became a little concerned at how all this material will breakdown into lovely ready to use humus. Though the heap is hot and obviously some breakdown is happening, most of the the ingredients can be identified as their orignial state ie: straw, comfrey, hay, bracken etc.
I am wondering if we are on track or what condition the materials should be in on day 10?
I have taken photographs if you would like to have a look at how its doing.
Thanks again for all the advice and support.
Julie
Hi Julie,
If the temperature is in the 55-65 degrees celcius range, it’s on track, it should be OK. You’re only half way there right now, the breakdown of the material speeds up as the bacteria multiply exponentially, and there is a lot more of them to consume the compost materials!
Remember, around day 8 is when the temperature peaks, the next 10 days is the ‘slow bake’ period that will literally cook all the ingredients and break them down so they won’t be recognisable. The heap will be hottest in the centre, and the outside will naturally be cooler, which is why you turn it, so the outside material is put into the hot centre to break down. As mentioned in the article, if it starts to cool down, you can heat up the compost by adding a handful of blood & bone fertiliser per pitchfork when turning.
Please let me know how it goes after the 18 days, as I’m sure many people are curious how the process works in cold contitions.
Thanks
What an interestingly well written site. I seem to fall into the notorious 10% of people who still have things to learn and add to my 50 yrs. of trial / error frugal gardening..
Born and bred in the N. Texas sparsely wooded black-land native grassy prairies, between ‘temperate zones” ranging from well below 0 degrees F to 114 degrees F, I chose to Zeriscape about twenty years ago, having learned from a N. American university -who’d successfully beaten the dreaded weeding/ watering drudgery with the right formula utilizing local available free materials and recylables.
[I’ve nearly died with every sort of compost formula’s molds,
fungus, and failed results, heavy labor, suggested DIY contraptions, and guesses, learning that few are designed for this zone/ temp
fluctuation and unpredictability/ toxicity we have here in city water, air pollution, [GMO/ hybirdizing of seeds], chlorine-gassing of most retail-sold vegetables and fruits, ignorance of “recommended pesticide useage’ by so-called ‘local experts’, laws growing agianst local organic farming, wrong and/or omitted important information resulting in greatly compromised immune systems of my large urban corner home and yard, as well as my slightly oversized but weakened, aging body! It’s enough to make an old gardener to give
up.
Have I? Nope. Like Thomas Edison, I have learned from hundreds of things and ways that don’t work ! It’s been a full circle of back-to-
basics/ Garden of Eden– thinking, greater common sense -regardless of ‘latest ideas’, and I now have a wonderful organic biosphere with VERY few, if any, pests or diseases, and several crops that have both grown and encouraged me to use all I have observed, re-thought, analysized, and concluded…to my full advantage, thanks to the Grace of God !!
The frequent feeding of the birds, squirrels, and observation of the advantages to having them,I more fully appreciate my variety of lizards and non-agressive ants, as God helps to balance it all. I’m having good success with top of ground, non-turning, cold composting, with the local vermi-culture/ beetles/ a few wasps/ and refuse from my wonderful, fat 3yr. old house-hen, 4 yr. old house rabbit [both contained in large waist high cages-cleaned-daily], along with a treasure-find of an electric ionizer/air freshener which totally eliminates any odors in ten minutes!
With weather extremes, black clay soil, frequent lawn-watering restrictions because of weather extremes?, and many trees/ shrubs, I’m trying to find ways to work within my boundaries, to preserve my VASTLY diverse landscape and strange EDIBLE native-plant takeover of my back yard. [Just thought I’d drop by and share from a reader of another region’s dilemma and to say,”. Keep up the good work; don’t give up, even on the white/black/green/red/ orange funguses !! or on learning. It’s both a challenge and a TRIP.
Lynda
Updating, moved temporarily to the near countryside. Discovered that, in old home needing repairs, that my entire garden and flower beds were literally crouded with the largest most incredible GRUBS, not the usual ones, but gi-normous ones. Learned that my compost was so rich, plentiful, well decomposed that it was THEM who turned it into what I hoped it would be, but cannot use after all?
Downside: They continued eating the roots on everything smaller than a tree root!! Called the most reliable organic growers/retailers whose best horticulturist gave me the bad news: NOTHING so far is able to phase these creatures because they are particularly LARGE
and from ASIAN beetles [metallic variations on backside] that do NOT respond to Milky Spore. Since I’m all organic, I am searching frantically to find a natural deterrent or host to keep them at bay.
Any ideas or ‘latest news’ re these HUGE, nearly [small] chicken-leg sized grubs would be deeply appreciated. My yard is almost DIRT now and the most discouraging info says there is NOTHING I can do short of eliminating the dream of lawn/ bedding repair, and to plan
for ‘hardscaping’ instead.
So, unless some reader with additional info has a better idea, I’m going to pursue shadecloth under gravel meandering paths, repositioning my tub garden and bird baths, and streamline using what I already have but expanding into the lawn. According to the advice, I may even have to resort to artificial plants!!
Of course this situation may change if the coming extraordinary heat predicted for Texas is a reality, which just MIGHT penetrate deep enough to COOK whatever larva which may be lingering, getting hungry – having been so greedy as to eat both compost AND root system of the majority of my large corner lot!
It’s like a bad SCI-Fi movie, but God is good and may answer my prayers of distress. Afterall, He knows all things, including just HOW these beetles and grubs became so large, as well as what to do about it! What a dilemma!
The permies say… You don’t have a slug problem … You have a lack of ducks problem.
Can you use sulfate of ammonia (N) in the place of greens? Will it aid in the brake down of the carbon material and heat the compost pile?
Hi Harris,
I would NOT use ammonium sulphate in my compost, it’s a strange practice that non-organic gardeners are recommending, and I think it is a very bad idea.
Here are a few reasons to consider:
Ammonium sulphate is acidic, you don’t want ti acidify your compost.
It’s a mineral salt, so in quantities significant enough to contribute nitrogen, it will possibly be too high a salt concentration that will disrupt the bacteria and fungi in the compost pile ecosystem, and will probably slow the composting process down.
Compost is not just carbon and nitrogen, these are just the major elements that bacteria use to consititute themselves from as they multiply, but you need lots of other elements and substances in there too for bacteria to grow and break down the organic matter, and for the resulting compost to be useful as a plant food, which is ultimately what we want the compost for. Green organic matter contains all the other substances that aid decomposition.
Using a wide variety of ingredients creates the richest compost, which will be best for your garden. Using very few ingredients will make for a lower grade compost.
You have to pay for ammonium sulphate, and other than being unsustainable, having to pay for a nitrogen fertilizer is crazy, considering that is what all living organisms excrete as bodily waste!
I personally would discourage the practise, there are so many nitrogen sources freely available that the need to put chemical fetiliser in your compost would be hard to justify. It would really be easier to just urinate in the compost heap a few times if you needed to top up the nitrogen, seriously. You wouldn’t just use this as the only nitrogen source, since urine can have high sodium levels, we excrete salt this way, and you don’t want high salt levels in your garden either.
Just look at the list of nitrogen sources I have listed, there are 17 of them there, and there’s lots more available I haven’t listed, I’m sure some of these must be available.
Keep it all natural and organic, and you’ll be much happier, and so will your compost!
Regards
Thank You. I’ve been looking for a better explanation on Hot Composting. I just like doing things in such a way that they require less work from me. I saw a special that featured African woman in this village that collected all the food waste in a special roofed area where they had three piles: new, once turned, twice turned. As it composted the piles were turned and a stick pushed into them. To check the temperature they pulled out the stick and touched it to make sure it was nice and warm. The finished material was put into their gardens.
But, as we are running out of oil we should stop composting and look to get the most out of every calorie we can get. To replace composting collect all animal and human poop (pee too) as well as plant materials from the garden and kitchen. Slurry them (about like running oatmeal) and pour into a methane digester. What you get is methane and a high quality fertilizer. Two things where before you had one. More bang for every calorie.
Hello,
I was wonderin if you can collect your composting material over a period of time? I dont have that much material ready at once, but I throw all my kitchen scraps in the small bins I have for that in my backyard. Can I keep collecting the material and then start a big pile at once? Or can I use this method with small bins?
Thanx in advance.
Yes, you could gather your compost materials over time, and they will start cold composting where they are stored but that shouldn’t be too much of an issue, you will just lose some of the nitrogen content. Pile it all up when you have enough materials, then add some extra nitrogen materials (greens or manures) because nitrogen gets lost over time when storing the materials.
You can’t hot compost with small bins because you need a minimum of one cubic metre of materials to get the hot composting process running.
Regards
I have tried my first ever hot compost pile thanks to your excellent info. I wanted to share my experiences.
I’m in inner city Melbourne Australia
Because of lack of space I had to make a 1 metre square pen with chicken wire. I used veggie scraps, shredded green garden prunings, shredded dry leaves, lucerne hay, manure, molasses, partially broken down compost from my tumbler and smaller bin.
I built up the pile to 1 metre square in 3 stages because I didn’t have enough materials in the beginning so I think the highest temperature I got to was 45 deg Celsius. I added some blood and bone at the second and third stage because I thought being built up in this less than ideal manner a nitrogen boost could help raise the temperature. Don’t know if this was a good idea or not.
I lined the pen with hessian and then covered the top with hessian and a tarp. Because of the pen I couldn’t do your outside to inside turning method. My method was to shovel it all out and shovel it all back in again, mixing and breaking up clumps.
I got some white powder at a few stages on materials in the pile like lucerne hay. This was towards the top of the pile so I didn’t think it could be due to excess heat. I was wondering if it was because I didn’t damp this layer down enough as I noticed it was dry.
I used a mask over my mouth and nose when turning. But stopped using it towards the end when I didn’t think there would be airborne bacteria.
It’s broken down quite nicely although of course it took a lot longer than 18 days because the bulk wasn’t there. It smelt good at all stages. I now have a lot of small, fine twiggy bits throughout and I was wondering if the best way to deal with this is to sift the compost so I can use the broken down compost and save the twigs for the next compost pile. I was thinking this might be the way to go because now that its lost its heat the twigs will take a long time to break down.
I was interested in any thoughts on how to improve my process next time.
And was particularly interested in the best way to build up a bulk of materials. I have a small garden so gathering materials takes a while.
Am I best to shred everything as I get it and put it in my tumbler and small bin and then transfer it to the hot compost pen with new materials when I feel I have enough bulk.
Or would it be better to just let the garden prunings sit without breaking them down and carry on with composting the veggie scraps in the tumbler with the appropriate balance of dry materials. And then when I have the bulk, mixing them all into the hot compost pen.
I want my materials to be in the best shape they can be by the time I have the bulk to begin the hot compost.
Any thoughts would be most appreciated and thank you for such a great resource.
hi, if I need more carbon than nitrogen and storing depletes the nitrogen, then should I really have to add nitrogen back in, surely the ration of carbon to nitrogen will travel towards the correct ration for hot composting as nitrogen rich items are stored?
I am interested in this specifically as I do not have enough carbon and am attempting to dry (through storage) some of the naturally nitrogen rich items to obtain carbon rich items, to store until I have enough material for a heap, i.e. I leave cabbage and other leaves, grass clippings, etc. out in the sun to dry then store them when they are crispy and brown looking to mix with freshly gathered of the same items. Is there a problem with my logic?
I’m surprised that you can’t find enough carbon, it’s everywhere, newspapers, cardboard, fallen leaves and woody mulches are all very rich in carbon.
Lawn clippings are already have the perfect C:N ratio, so it is very efficient to try dry them to lose nitrogen so you can use them as a carbon source.
The flaw in the logic is that the materials such as kitchen scraps or lawn clippings have adequate carbon, what you’ve overlooked (and I failed to explain…) is that they’re primarily water! Think of how light fully dry grass clippings are, a bucket full will literally have no weight, so when you take out the water and the carbon content is quite insignificant. Most nitrogen-rich materials contain a lot of water, and therefore very little carbon as a percentage of their weight.
Hope this helps!
I was thinking of building a hot compost pile in my front yard before I build some large raised garden beds for veggie growing. There is space now but won’t be later. I was wondering if there is much smell. Would my neighbours find it a bit wiffy?
Thankfully, there is no smell at all once its all built. The first hot compost pile I built in a friends small backyard, we used bags of very smelly fresh comw manure we collected from a farm, when the compost pile was built and watered, no smell whatsoever.
I’m not sure I understand the 30:1 ratio. How is that achieved given the various ratios you show above. I mixed alternating layers of old compost, dried leaves, and manure to build my new pile. How can I tell if that will give the correct ration
Hi Scott, you can use simple cross-calculation for the ratio.
Assuming we’re only using straw (C:N ratio is 75) and chicken manure (C:N ratio is 12) for the compost (C:N ratio is 30), here’s how we can calculate it:
Straw: (75) x 18 = 1350
– =
Target: (30) :
– =
Manure: (12) x 45 = 540
=
2.5 : 1
First we put the C:N numbers we know from our materials and the target in its places (x). Then we diagonally subtract the bigger number with the smaller. After that we multiply them horizontally, in the example straw’s C:N ratio is multiplied by the difference between target’s and manure’s C:N ratio. The two resulting numbers are the ratio for the ingredients. For this example we need around 2.5 part of straw for each 1 part of chicken manure. Based on the C:N ratio data, the ratio should be based on material’s weight, not volume.
However, I just know how to deal with two ingredients using this method. Anyone knows how to calculate C.N ratio of multi-ingredients?
ABSOLUTELY NOT NECESSARY ! (but read all to understand why and an “easier method to do”)
Lets say C:N target = 30
SUM = {30/C:N(1) + 30/C:N(2) + 30/C:N(3) + … + 30/C:N(n)} = let’s say “Y”
If pile = 1,5m (=1.500 dm) (= ??? forks ? to determine, but don’t !)
==>
[{1500 x C:N(1)} / Y] = quantity C:N(1)
[{1500 x C:N(2)} / Y] = quantity C:N(2)
[{1500 x C:N(3)]} / y] = quantity C:N(3)
…
…
[{1500 x C:N(n)]} / y] = quantity C:N(n)
For example (if C:N target ? 30:1) and I have wood chips (400:1), garden waste, weeds (30:1) and cow manure (16:1), that give :
30/400 + 30/30 + 30/16 = 0,075 + 1 + 1,875 = 2,95
Parts :
C:N(1) = 1.500 x 0,075 / 2,95 = 38 of the 1.500 parts or 2,53% (+/- 3%)
C:N(2) = 1.500 x 1 / 2,95 = 508 parts of the 1.500 parts or 33,87% (+/- 1/3)
C:N(3) = 1.500 x 1,875 / 2,95 = 953 parts of the 1.500 parts or 63,53% (+/- 2/3)
HORRIBLY LONG, COMPLICATED AND, ABOVE ALL, ABSOLUTELY NOT NECESSARY!
Let’s try DIFFERENTLY since we know that an “approched” outcome is more than enough and, let’s work in “forks” (units) whatever the density of the avalable components (in composting, approximations are very broad : 1 “green” to 2″brown” is a glaring proof of that !)
Returning to our previous results, we have “approximately” :
1500 x 3% = 45 – 1.500 x 1/3 = 500 – 1.500 x 2/3 = 1.000
wich gives, with a broader approximation, but considering “fork” units a proportion like this : 5 forks wood chips + 50 forks garden waste and weeds + 100 forks cow manure,
Also, not that easy, BUT… observing this “expression”, it enables us to make extremely simple distribution calculations in practice : let’s replace the C:N in the table (once for ever) by “forks” (or units), based on the weeds or garden waste, (everybody has that!) .
This will render the job very easier (the easiest way for me) :
+/- 1 fork wood chips = +/- 10 forks weeds or garden waste
+/- 2 forks cow manure = +/- 1 fork weeds or garden waste
+/- 1 fork leaves = +/- 2 forks weeds
– a.s.o. …
So, if I have 10 forks of wooden chips, I mix them with 100 forks of weeds;
if I also have 50 forks of cow manure, I mix them with 25 forks of weeds;
and if I have 50 forks of leaves too, I mix them with 100 forks of weeds, a.s.o
Then I mix all those little mixings together to have a rich compost.
This is like my ‘buckets’ example, where it’s done by volume, but we add one bucket of nitrogen-rich (green) material to every two buckets of dry carbon-containing (brown) material.
When the universities publish articles on making compost, they do a laboratory analysis of carbon, nitrogen and WATER.
The water level is the critical factor, and many green materials contain a lot of water, and many dry materials contain a lot of air (where the water once was).
The concern about using “10 forks of wooden chips, I mix them with 100 forks of weeds” is that instead of using 2 parts brown : one part green you’re using one part brown : 10 parts green which will most likely get too damp, soggy and anaerobic.
Hi Scott, you can use this simple formula to guesstimate your compost ingredients.
Ratio of ingredients =
[CN1 x (CNtarget-CN2)] : [CN2 x (CNtarget-CN1)]
In principle we multiply the C:N ratio of the 1st ingredient with the difference between 2nd’s and target, then compare it with the number we get from the opposite.
For example if we’re using only straw (C:N=75) and chicken manure (C:N=12) to make compost (C:N target = 30), here’s how we calculate it:
Ratio of straw : chicken manure
= [75 x (30-12)] : [12 x (30-75)]
= 1350 : 540
= 2.5 : 1
Please note as what we need is the differences, negative number is not a problem. Ratio of 2.5 : 1 means we would need approximately 2.5 kg of straw for each 1 kg of chicken manure. However I only know how to deal with 2 ingredients with this method, anyone knows how to calculate ratio with multi-ingredients?
Angelo,
Many thanks for your prompt answer.
I must admit that I do “cold” compost. There is never a bad smell but my heaps reduce greatly, what attempt to give you reason. I also cannot control the carbon / nitrogen ratio at the end of maturation.
Early, years ago, I used the ratio 2 brown/1 green. Results in reducing of the heaps were approximately same. You need a big quantity of “hard” brown matters to avoid that reducing heap.
But… if my calculations are correct, the interpretation thereof is too. Otherwise…
Assuming that I only have two available materials: wood chips (400:1) and weeds (30:1), HOW to get an average ratio of C:N ? 30:1 by mixing these two components? No calculation allows that!
Only green materials at very very low carbon ratio can “reduce” the amount contributed by the wood chips. But in this case, it will still take a huge amount of these green materials relative to browns! If this is not the case, I don’t understand how the C:N ratios (given all over the Internet) may help and, above all, what’s the interest to know them since calculations give all in all fully inapropriate results?
Many thanks then for comprehensive explanations of the “how to”, to get the “correct” calculated proportions in the mix with the easiest to find matters : weeds, wood, leaves, fruit + vegetable + garden waste, green wood and some animal manure (only curiosity).
If you want to understand the mathematics in detail, Cornell University’s Waste Management Institute has a great explanation of calculation the C:N ratio of ONE material here (http://compost.css.cornell.edu/calc/cn_ratio.html). You’ll notice you need the mass of material (wet weight), the carbon percentage of the material, the nitrogen percentage of the material, and also moisture content (%) of material!
When you’re mixing two materials, the maths gets even more complicated, and Cornell’s site explains that here for a mix of up to three materials: (http://compost.css.cornell.edu/calc/simultaneous.html).
They also have a calculator that will calculate the final C:N ratio “Calculate C/N Ratio For Three Materials” here: (http://compost.css.cornell.edu/calc/2.html) but you need actual weights of materials, and the real percentages of C, N and moisture once again.
Many people make hot compost without ever looking at the maths and it works great!
The C:N ratios listed here and on other sites are educational and their purpose is to demonstrate which materials have what amounts of C and N to understand how to use each material, and to recognise that that some nitrogen containing materials contain a lot more nitrogen than others, and likewise for carbon rich materials.
Wow…
Well…
Finally… 2 browns for 1 green is easier ! LOL !
Well, I definitely agree with you on that one!
The very first hot compost a colleague and I tried was a success, and we didn’t overthink the C:N ratios. As Albert Einstein once said ”
Everything should be made as simple as possible, but not simpler.”
2 browns for 1 green is as simple (and effective) as it gets. 🙂
If the Berkeley method will compost dead animals, then surely you could safely add some humanure into the mix, which is full of like pathogens.
It would greatly encourage the composting of human waste if it was made know that it could be safely turned into compost in 18 days.
I suspect that no one wants to advocate this for reasons of cultural sensitivity or legal liability, but it’s time we thought through this apparent contradiction. The potential benefits are too big to ignore.
I’ve personally never seen hot composting used to process humanure ever, we can only guess at the reasons why. In rural areas in Asia whole countries us it unprocessed straight in the fields where food is grown, but they don’t eat raw vegetables, they cook or stir fry everything, so any pathogens probably get eliminated that way. That’s the cultural safety practice.
If the site is big enough, human waste can be processed continuously on site with a natural sewage treatment system – aerobic digesters that use bacteria to break everything down, then the resultant waste is passed through reed beds planted in gravel, then what comes out of this if fairly safe and is used to irrigate fruit trees. I believe Michael Reynold’s ‘Earthship’ buildings process all human waste onsite and use the outputs to provide water and nutrients to orchards near the house. Guess this is getting off the topic of composting though…
You can compost human manure you just need to make sure you get it hot enough. You are probably still best to use it for trees or bushes rather then using it on the vegetable garden. I have worked on an organic farm where a retired Environmental Scientist had a system for composting human manure. I read about along time ago how in New England there is some human manure treatment plants where human manure is broken down for compost (using bacteria) and sold to the public. Once any Nasty bugs have been destroyed the only issue I guess would be any medications people had been taking, which might be high in certain toxic minerals.
Thanks for the response. Yes, I know the three stage natural sewage treatment system as detailed in the Design Manual, but in relation just to hot composting, isn’t it interesting that no-one utters the “h” word?
I have the videos on-sale at the Tagari site of the PDC given by Geoff and Bill in Melbourne in 2005. In it, Geoff goes through the complete 18 day system. He also tells anecdotes about using the system to compost a wallabee, a duck,and road kill of various kinds. Never, though, does he mention humanure, nor does anyone ask him about it. Curious.
Unless and until I hear otherwise, I’m going to assume that the temperatures reached by this system are plenty high enough to render harmless anything in reasonable amounts of humanure composted in this system.
Hi,
Thank you very much for this information.I have based my own compost making on the method you have described.Your post explains the science behind composting in an easy to understand manner.
Hi. Great article! Thanks for writing it.
We’ve been cold composting for years but are now trying to compost, and I have a couple questions about the 18-day method.
1. We put our raw materials in cube-shaped compost bins that have slats on their sides, and we cover the top with canvas. Is covering a bad idea?
The reason I ask is because we typically get some fire blight in the middle of the pile, but the heap never gets above 65C. The pile does not smell bad.
2. The heap consists mostly of rabbit manure: dry timothy hay, pine shavings, rabbit pellets, and some rabbit urine. Does that sound like the right mix?
I’ll appreciate any guidance you can provide.
Thank you.
jp
As I mentioned in a previous answer – “The compost heap is normally covered with a tarp or plastic sheet, to prevent the rain cooling it down, since the water penetrates into the core of the compost pile. Cold outside air will cool the surface, but not the core of the compost heap. The covering prevents some heat loss from the surface to cooler outside air, and retain the heat within the compost heap better.” I’ve updated the article to add this information, as this is an important point, so thanks for asking. Short answwer is no, covering is not a bad idea if you want to retain heat and prevent the heap getting waterlogged from rain.
If the heap is getting fire blight, it might actually be getting over 65 degrees celcius, depends if your thermometere is accurrate enough and long enough to reach the centre of the compost heap without digging it open. Leaving the top cover off for a while will coll it down a bit.
Your mix includes all the right ingredients to supply carbon and nitrogen, you just have the ratios correct, if the heap shrinks in size, add more carbon, if it’s not breaking down, add more nitrogen
Thanks for the response Blackthorn.
Do you know where I can get a picture of fire blight? Maybe what I’m seeing isn’t fire blight, because it seems worst on grass, for example, glass left inside the lawn mower will get white stuff on it, too.
How can you tell if the pile is actually shrinking? Our pile has a good chunk of dry straw/hay, which tends to hold a lot of air, so it’s hard to say if the pile is settling or actually shrinking.
jp
Don’t have any pictures of fire blight, but it’s very easy to tell if the compost heap is shrinking, it reduces in volume drastically. If it’s just settling, it’s only a small change.
Ive been hot composting for about 30 years. I spread it out in layers then run my Troybuilt tiller thru it many times before piling it up. I primarily use leaves and grass clippings but also kitchen wastes. I have never used a thermometer but I know it gets very hot. My question is after reading this Im pretty sure I have been getting fire blight for years. I make many large piles yearly to put in vegetable and flower gardens. The finish product is broke down, looks and smells good. Can you tell me what the problem is with the pile getting to hot. Im guessing maybe mold spores while turning?
If your hot compost is getting too hot, it just indicates that you have excess nitrogen, so it’s best to make better use of the composting materials by adding more carbon-rich materials, such as wood chips, saw dust, dry woody material etc, so you can produce more compost without having any nitrogen escape back into the atmosphere. Green leaves, grass clippings and kitchen wastes are all high in nitrogen, so you need more carbon containing materials. You could collect autumn leaves and store them aside for adding into your compost if you can’t source wood chips, sawdust, newspaper, cardboard, straw, etc.
The problem with the compost heap getting too hot is that it runs out of oxygen and anaerobic thermophilic composting bacteria take over, which changes the whole chemical process of the composting. Aerobic breakdown retains the volume of compost, as well as a lot of nitrogen, which is a valuable macronutrient required for plant growth. Anaerobic breakdown releases lots of carbon and nitrogen back into the atmosphere, and the compost reduces in volume, as well as becoming more acidic.
I dont feel I have any of the adverse conditions happening. There have been times when the smell (ammonia) would be bad but havent had that issue in years. If the wind was blowing up towards the house my wife would let me know it. I guess my nose is my thermometer but it would be interesting to use a thermometer and see how hot it gets. I have one pile thats about done (17 days old), one thats 8 days old, and started a new one yesterday. I mow two acres with a lot of trees and have a Cyclone Rake yard vac that I pull behind my lawn tractor so I have plenty of material.
I have two composts heaps in dustbins – one to keep filling, the other left to do its thing. This has all worked well enough – the temp in the one I add to is usaually around 35- 40C in the spring / summer / early autumn and produces good compost over perhaps 3-4 months once I’ve stopped adding new material.
The question I have is about what happpens towards the end of this 3-4 month period. Not always, but frequently, when I look in the bin in process of decomposing, ie not having new material added, the compost is starting to appear or is near completion and yet for some strange reason, when I take the lid off to have a look and see how things are going, the lid and near the top of the bid, are covered with sometimes a few, often loads, of small, wriggling red worms – all trying to escape from the bin, just when I want them to stay in the bin for them to finish their good work.
Do you know why this happens?
I have read that it has something to do with too much moisture, but this doesn’t make sense as the heat has generally cooled off a bit and although the underside of the bid lid is a bit damp, it doesn’t seem quite right.
I usually put those worms that are trying to escape into the more active bin, but suspect others do manage to escape – not that it really matters, I am just curious!
With thanks
Jonah
________________________________
Hi Jonah, earthworms don’t want to be anywhere near composting material while it’s in the process of composting, they only visit when the composting process is completed. Bacteria carry out the composting process in compost bins, and the chemistry in there is not something the worms can tolerate. In summer, a sealed compost bin gets awfully hot too! In worm farms, earthworms come to the surface when the air pressure drops, which happens when rain is coming, thy come up so they don’t drown. Hope this helps!
Thanks for your prompt reply, Angelo.
So, after all these years, I now realised that worms do not take part in the composting process….How could I have not known that. The ones I have trying to escape are thin, red, wriggly worms, often quite long…. and they are nothing to do with the composting process? How come they are in the manure from the farm when I go to collect it?
With thanks again.
Jonah ________________________________
Earthworms and compost worms do their own composting, it’s called vermicomposting, that’s what happens in a worm farm – see my article – https://deepgreenpermaculture.com/diy-instructions/worm-farming/
They don’t produce compost though, they make something far better, the best fertilizer available, worm castings!
Composting is best for garden clippings, leaves, mulched branches, and lawn clippings, and it’s a slow process taking months, hot composting is the fastest and is completed in 18 days, which is 2/3 of a month . Worm farms only process fruit and vegetable kitchen scraps and a few other things, and consume material daily, it’s an extremely quick process. The worms are in the manure because it’s their job to break it down, it’s what they do in nature! ?
Hi. I have been attempting this method with two large piles. One 8cu meters of horse manure and straw and the other 40 cu m of chicken and wood shavings. They are tarped with black vinyl. The average outside temp in the day is 38c. I turn them with a backhoe. If I don’t turn for 4 days the pile temp will go up to 55-60. The problem is that when I do turn the temp drops to 47 or so and takes a few days to build back up. Thanks!
Thanks for the idea of ducks for the beetles that produce the ginormous grubs I have….soon to be new beetles! Problem with having ducks is that there is a local ordinance against them, and they must be fed daily, which is impossible since I’m living temporarily away from the home/garden while it gets upgraded/ remodeled as I can pay for it.
I LOVE ducks, and there are plenty in this city at the local parks, but they need both space and water, which I don’t have…even if the city allowed them in the neighborhoods.
True story from a casual acquaintance of ours who described finding a duck nest full of hatching eggs ..but without the mom: He took them home, nurtured/protected/raised them, only to have neighbors call the local police about their noise.
He said he had hoped to get them far enough along to release them in the park so he went to court and lied about the situation, saying, “The report you received was all wrong. That wasn’t noise from ducks but from DOGS!” They believed him, buying a little more time, but the neighbors persisted until police visited and took the ducks. Hopefully they released them rather than ate them!
Thanks again for the good advice.
Great article. I have two big piles of organic matter that I’d like some advice about. First, five bags of hedge clippings that might have some bittersweet in them–do I count them as green or brown? Right now its seems to be both. Wait until it’s all brown? I also have one precious bucket of horse manure that I thought I’d mix with food scraps as starter. The second pile is mostly forsythia that I cut down a couple of weeks ago, and as careful as I was, its even more likely that there’s bittersweet and Japanese knotweed in that pile. It’s basically a giant pile of branches. The good news is that since I’m constructing a woodland garden, I’m don’t even want perfectly fine soil, I just don’t want it to sprout demons.
Don’t wait for the green material to dry out and turn brown, you’re losing valuable nitrogen that way, carbon can be found very easily. Turn the whole lot into a huge hot compost pile to kill off all the weeds, and try to break down all the branches into smaller pieces however you can, mulch them, mow then, cut them up with a sharp spade – the compost works better when all the ingredients are broken down into smaller pieces.
Thanks. I kind of decided to “split the difference” with regards to the pile of hedge clippings. By that I mean I’m just not up for hacking up all those twigs. If you’re not familiar with the obsequious American hedge, you should know the twigs are pretty springy, going at them with a hoe wouldn’t work. I’d guess they’re 70 percent nitrogen; add in the leaves on the twigs, and my 2 m around pile might be too green if it weren’t for the larger twigs and the fact that it did die down a bit. Now it’s a 1 m tall twiggy donut with a horse manure-food scrap center! On Sunday I’ll turn it for the first time and decide then whether to add some cardboard.
My “bittersweet” neighbor has expressed some dissatisfaction with her cardboard and branch yard, so I’m going to leave it be.
Hi
Have just retired to the beautiful and remote Creuse department
in the Limousin in France. Have bought a 6 acre plot about half is mixture of mature oak and Beech, there is a lake of about half an acre and the rest is neglected long long grass which i am very slowly taming with strummer and mower. We are vegetarian and plan to start growing as much as possible next spring so am composting everything in sight as fast as possible to help fill raised beds. I am passing everything apart from grass cutting through a broyeur (shredder/chipper) so apart from the cardboard “removal boxes” its all very small. Two heaps so far about 4m2 each. The first i didn’t water enough so was running at about 35-40C The second I did and its at 65-70C, even 60C just 2-3 inches in – both have the same sort of mix. I turned the first heap today and watered as I went so expect temperature to rise. My problem is I have a bad back and the turning today which took about 90mins has left me with a lot of pain. I just cant see me repeating this on a 2 day turnaround, especially with several heaps. I would appreciate some advice to ensure readiness for next spring with the minimum of back pain! Thanks for a brilliant article.
Hi Chris, I would use smaller compost heaps, something closer to the size recommended in the article, around 1 metre square and a bit taller than that. A 4m x 4m x 1m pile is huge! That’s back-breaking work in anyones language, sound like something you would tackle with a front-end loader!
Smaller heaps are much easier to turn, around 15-20 minutes. Since you have to complete turning a heap once you start doing so, if you have several smaller compost heaps, they are much quicker to finish, so you can have a rest much sooner, that way the work is not as tiring and drawn out as turning one big heap.
Furthermore, by having multiple smaller piles, you can have a good rest after finishing each one, and when you are refreshed and re-energised, you can tackle the next. Thos allows you to spread the work out over the length of a day. For example, you could turn one heap in the morning, then another a few hours later, and so on.
As predicted after 2 days, the newly turned first heap is hitting the heights at 65-70C the first and previously 65-70C second heap is falling back to 50-55C
Haha – no 4X4X1 would be 16m2 mine are 2X2X1 but still twice what you recommended – will give smaller ones a go though, it will help I’m sure – thanks
Ah-hhh, our dreaded Texas summer is cooling down, but “the whole state has been plagued with mosquito-carrying West Nile Virus, causing a fairly large number of deaths.” Being so efficient, the city officials? or some authority has sprayed the entire STATE with ‘relatively harmless chemicals’ THREE times over a few weeks, causing a noticeable dullness of life in everything living.
It certainly put the skids on gardening hopefuls, and likely gassed
the many compost piles in the making with their concoction of only God knows what! [ Right away we found a poor dead Morning Dove who’d been feeding from the neighbor’s tossed bird seeds. So much for “harmless”.] Now I’m wondering how many more creatures will go the way of the bees -which have all but disappeared here ov er several years now!
My grub problem has not changed, yet the lawn in the temporary
home I’m renting has signs just like my other home-in-repair of grubs beginning at the edges of the lawn!!
With all of the genetic modifications/ mutations/ hybrids/ cloning,
even science [and Monsanto] likely doesn’t know or care what all they’ve altered/ created, much less how to rid our land of such things. We’ve sent more soil samples to the state agricultural extension center for analysis, waiting for some suggestions before blow-torching the remnant sparse stubs of well-established noxious weeds, wild carrot and wild garlic, which the omnivorous zombie grubs seemed to have rejected!
Yes, this sort of global bio-manipulation tends to make one pessimistic, frustrated, as well as outright ill. Although there must surely be myriads of researchers who have hopeful suggestions, but our arms and pockets are fast becoming empty for such challenges that are not of our own making/ budgeting.
The lawn responded to the first application of “recommended” [against my better judgment fading fast] Golf Course chemical fertilizer….for about a month, but our cheering it on, watering to near indebtedness to the city utilities, manicuring to an ‘exact science’, the results is nearly the same as before we started.
Luckily our property is not at all the only affected one.
Thanks to you, Julie, for the duck suggestion last July, but our city deed restrictions/ homeowners’ association refuse to permit us to have such helpful creatures within the neighborhoods. I still have my house-chicken and mini-Rex house-bunny in lovely large well-built rolling cages, but cannot let them freely roam outside, even inside my fence, because of the wild creatures the city protects – and which are attracted to and eat such animals. We have Owls, Hawks, O’possum, Raccoons, occasional foxes, Coyotes, abandoned domestic and exotic animals turned loose when someone moves, and hefty resident rats which are said to eat
the feet of chickens as they sleep!
So why am I writing? Just in case someone runs across another
soul like me, who might have an alternate solution to the blow-torch, [which would only take care of the tough dry stalks which we have also considered spray-painting GRASS green! lol If some of the local landscape companies can tint their seeded foam, it would be a big temptation even for you!]
Wish I could send a photo of it but we still have a few large spreading and tall old trees making a photo near-impossible. Hum-mmm, anyone know whether too many fallen acorns can ruin lawns over the years? We’ve always just mowed over them. They likely just fed more grub-bellies, right? Wouldn’t this scenario make a good video/board game : “Conquest of the Zombie Grubs”
with a sequel: “Protectors of the Zombie Grubs”.
[My grandson would likely want to develop this whole concept since his goal is to be a computer animation programmer of new games for teens and young adults. He’s currently reading every Anime book he can find for ideas. I’ll suggest this to him tomorrow and have my cellphone camera set for his laughter!] I may as well laugh, since I’m nearly out of tears, hair, and money!
Hi, to be honest I’m not sure what your point is here in regards to hot composting, if I did I’d try offering some help…
I know its some time ago this post was made, but why not abandon the lawn, If nature doesnt want it to grow, do something else with it. Grow what grows well is my adage where slugs and clay make growing a nightmare unless I follow nature.
Oh, might I suggest that NO one add litter-box residue [fresh or otherwise] nor ‘roadkill’ to their compost, because of the good possibility of diseases. You were just kidding, right, when you mentioned, “anything” can be added to the hot compost?
Linda, pathogens are destroyed by the hot composting process, but not by cold composting.
Our good neighbors began a compost pile the lazy way by just tossing all grass and a very few veggie scraps into a pile over a couple of years. [ It became the S.W. distribution of flies, rats, and whatever else since it was, to my knowledge, never turned by hand, but did indeed turn to blackest dirt.]
My son agreed to build their new fence when he built mine, with the understanding that he’d single-handedly move their pile to fill in our holes left by larger tree roots, to which they agreed.
Within a few weeks, one of the few veggie scrap SEEDS sprouted and grew the largest, most delightful Acorn/ Winter squashes we’d ever seen . I collected six large ones, stopped by to share with them but they’d gone on vacation, followed by our doing the same, and never got to see them before we had to eat them. What a wonderful surprise with a supportive message: Seeds can indeed
survive most bountifully any compost pile, neglected or tenderly tended. I have chosen to be MOST careful to prevent my adding seeds of any sort to the next pile on the horizon.
No, seeds do not survive hot composting, what you’ve described is cold composting, and yes, some seeds will grow from cold compost, which is why, as a rule, you should not cold compost any weeds with ripe seeds.
The best article on hot composting I have ever read. It all makes sense now, thank you so much!
I now understand that our heap is too high in nitrogen due to the large quantities of grass clipping plus chicken manure. It is getting very hot and getting fire blight. It is almost like it burns itself out and then cold composts from that point on. We ended up with some reasonable compost in the end but it takes a long time and wasn’t all fine and unrecognisable like you describe. Definitely going to do it this way from now on.
The only bad part with doing it properly is having to go out in the pitch dark at night to turn the heap. The perils of working full time in the city I guess.
Dear sir: thank you for a very clear and concise article on hot composting. I have lived in Asia for 22 years and I’m developing a system for composting of humanure into humus for home and industrial agriculture in developing countries. My UDDT system separates human solids and liquids for several reasons & you finish up with two vital products in humus & NPK (urine) In India alone there are 600 million people a day who open defecate in fields because there is no (and never will be) organised governmental sewage collection system. Therefore collecting and utilising human waste products on a micro and macro scale has huge benefits in terms of ecological, geological, economical and human health and dignity aspects. I came across your wonderful site because I heard of hot composting and wondered if it could be utilised for humanure?
A couple of points about the western phobia about growing vegetables in human ‘poop’
If you think you are growing vegetables in human waste you are not; you are growing in organically rich humus, which, when properly processed through aerobic thermophillic composting has killed off pathogens at a temperature way beyond what the human body takes to kill of its own pathogens; in addition, it has also gone through the vermiculture process. You should worry about using industrial ‘fertiliser’ a.k.a. toxic waste, not humus a.k.a. organically rich compost.
Is it safe? Yes, according to WHO standards. http://www.who.int/water_sanitation_health/wastewater/gsuww/en/index.html
Faecal pathogens are dead after one week of composting at a sustained temperature of 122 f. When processed / composted properly from humanure to humus the compost contains no harmful pathogens. (WHO) Thermophillic composting often produces temperatures of around 150 f.
In addition I have been in contact with several members of the SuSaNa forum who have been growing in humus and using NPK (urine) for agriculture & salad plants for many many years.
FYI: Asians DO eat uncooked salads, quite a lot nowadays, as do I, but also extensively wok-cook / stir fry veg”s like beans, cabbage, carrots etc.
I will share with you once I (eventually) have my web/blog up and running. You should definitely put a programme together and go out and teach it in schools / community centres etc. We can save on fuel, carbon and land fill etc etc by taking personal responsibility for our waste products. Spread the word!
Best regards
Mike
Singapore
Composting human waste is a very good idea. I think a better one is to put both kitchen waste, urine and human waste into a methane digester to produce methane for cooking to not cut down any more trees and reduce indoor pollution and you also get a very high quality of fertilizer that you can put right on the land. This is something some Chinese have used for hundreds of years to keep their field fertile without soil depletion.
I hope this has been helpful.
Richard Boettner, Tomorrows Vision
I am trying to hot compost using shredded oil palm fronds which are half dried, peat soil as bulking agent and chicken manure. Can i use your method with these ingredients?
Will adding some compost activator help in the process?
I am located in johor, Malaysia with tropical temperature and climate.
Appreciate your reply.
Thanks.
It should work fine, as long as you have the right amounts of carbon and nitrogen containing materials, the bacteria will do the rest. Using a compost activator always helps, you can use comfrey, yarrow or nettles. Or you can pee into the compost heap! Adding a small amount of mature compost always helps to ‘inoculate’ the compost with the right bacteria. Give it a go and let us know how it goes!
OK, pee into the compost heap is fine, but how much pee will it take to destroy my compost? I can get all my family members to pee in it.
You only need to add a small amount of any compost activator once, it justs helps get the compost started. So, in answer to your question, one person, once, is plenty!
Will let you know the outcome in 2 weeks time since I am starting the process this thursday. And will as much as possible, follow your proceedures. thanks mate.
Hi,planning to build a hot compost while winter will come soon is it a good ideea?! Covered,outside or covered ,inside a part of greenhouse wich will not be used during the winter? if yes,what kind of manure is better to use,fresh or from the last three months? of course,will try to use activators but the problem is fresh manure or not? the temp will be soon below 30f(0 celsius)…
will try to increase the ratio of carbon till 40:1,or should i let it 25:1 ?! will be cows and horse manure….
From Romania,with admiration and respect for your work !
Cris
Hi Cris, to be honest, I’m not sure if the hot compost pile will cool down too much during such cold weather, because our weather never gets that cold here, so I would only be speculating.
Covered up, and inside a greenhouse should work, and it will warm the greenhouse too for a short time. Fresh compost will be the ‘hottest’ because it contains the most nitrogen, the aged compost will still work well though.
Don’t change the C:N ratio, because that is the ration that is used to make up the bacteria’s bodies, and it’s their activity that generates the heat. Excess nitrogen won’t be utilised and will probbaly just be released from the compost heap as ammonia.
It’s really a matter of timing, if you you can make the compost (in 18 days) before the weather gets very cold, then all will be fine to build it outside with a cover. If you want to make hot compost in freezing weather, all you can do is try and see what happens.
In Permaculture, we work with the cycles of nature and the ‘wild energies’ moving through our system/site – and one of those energies includes the natural heat from the sun. I would assume you would have the most materials to compost in autumn with leaf fall from deciduous trees, and green waste from your summer annual plants after harvest. This would give you some time to compost before the winter cold set in, and you only meed 18 days to do it!
First attempt failed in glory! 🙁
Succeded to rich few spots of 55 grdC ,but ,lack of personal presence for aeration ,…leading to a expected failure !
Now,spring is come again ,with fresh energy and more achievements!
Keep in touch!
I gave it a go. With so many autumn leaves it was silly not to. Tempatures this week are below freezing and I think it’s stopped the process. Yesterday while turning the pile for the 5th time on day 13 I didn’t see any steam like I had the times before.
I have been covering the pile. I’m curious if there are things I can try to get it going again?
Great article! Thanks. I have a question:)
Will pomegranate peelings break down as quickly as other “green” materials? It happens that I have plenty of them but also need quickly a lot of compost. Was wondering if it’s ok to use the peelings or should clip dome grasses? I really need compost in 3 weeks and as I have no experience in gardening/composting I thought I would ask:)
Thanks, Sebastian.
When hot composting, everything will break down! You’ll need to mix them with other ingredients as per normal hot composting practice. If done right, the ingredients will just vanish and create fine, dark, rich compost.
Blackthorn wrote on July 29, 2012 at 1:34 am:
“Ratios of carbon to nitrogen are the LEAST critical in a compost TUMBLER. Technically you could compost green grass clippings alone as long as you turn it daily, but its best to add a good mix of materials to try to achieve the optimum C:N ratio.”
[Emphasis added.]
~~~~~
I’m preparing a 58-gallon black plastic drum (once used to ship cucumbers in brine) for composting, and have a question about the air circulation.
There’s so much emphasis on the C:N ratio on the Web, but John Paul, Ph.D, P.Ag. (http://www.transformcompost.com/about-us.php), a noted compost researcher, also told me that in a TUMBLER, that ratio is less important than air circulation and moisture content. This confirms Blackthorn’s comment above.
Dr. Paul was too busy to give me specific advise about the number and size of holes to drill into this 58-gallon tumbler, so I’d appreciate your advise about that.
I intend to turn this barrel on its side and put in and take out the materials from the “top” end, which is a “bell jar” type design allowing one to open it by screwing and unscrewing the (entire) top.
I’d like to drill the holes only on the “original” top and bottom. Is that a good idea? (I don’t want to drill holes in the “original” side because that will allow all the “compost tea” to drain out onto the ground, and I want to drain out the “compost tea” into a special bucket only occasionally, using a single hole (with an on/off faucet fitting).
Thanks so much.
Definitely drill holes only in the top and bottom so you can collect the ‘compost tea’ liquid.
My tumbler compost bin is a commercial (bought) one, it has four holes on the outer edge of each top and bottom end, 8 holes in total.
The ‘holes’ are 3/4″ (19mm) in diameter, but aren’t really holes, they are a line of five slits that make up a circle shape. I’m guessing that’s to stop flies and other undesirable insects from getting into the compost bins.
However you make the air vents, make them up with a series of small holes if you can.
Hi,
We made a compost pile with mostly sheep manure mixed with some left over hay that was mixed in from what the sheep had eaten. But in the end it was mainly manure. We didn’t add much else. The pile is 6 ft high and 10 ft wide. We turned and watered it once a week for around 6 weeks. The highest temp we reached was 122 degrees and then the temp went down to 110 and we can’t get it much higher. It is turning black and the sheep pellets are decomposing. With our organic certification it is required that we reach 131 F minimum for 15 days. But we haven’t come close. I realized we probably didn’t have enough carbon so we added two bales of straw to see if that would help. But so far the highest temp is 110 F. Should we add more straw in layers between the current compost pile or is it too late because a lot of the manure has already broken down? We have the pile covered with a tarp as well.
Hi Tina, that’s because sheep manure is low in nitrogen compared to other animal manures, plus side is that it won’t burn your plants, minus side is that it’s not the best source when you need lots of nitroge. Hence the recommendation to use a mix of ingredients in your compost. Hope this helps!
If you could answer my Nov. 25 post, I’d be much obliged. This weekend I’ll be setting up the compost barrel system and need advise about the wisdom of drilling the “circulation holes.” On Nov. 26, Mary Schwarz at the Cornell Waste Management Institute advised against drilling any such holes and instead to ensure that the materials I use — she recommended “wood shavings” that contain much air / oxygen in lieu of “saw dust” — are carefully measured with the coffee grinds in the proper proportion. But I’ve never heard of a compost tumbler with NO circulation holes!
I’ve answered your original comment, please see above. The tumbler bins, and all compost bins for that matter, rely on aerobic composting, they definitely need oxygen, otherwise they go anaerobic and stink! You definitely need air vents!
I would only keep it airtight if I was using a bokashi fermenting anaerobic system, but that doesn’t need tumbling. The point of tumbling the compost, moving it, turning it, etc, is to get air into the mix to speed up breakdown!
Thank you for your responses. I’m still confused about where are the holes in your composter, since “top” and “bottom” and “side” are unclear to me. Can you tell me what is the model and manufacturer of your compost tumbler? That way, I can go and see a picture of it on the Internet / web site of the company.
I have a “Tumbleweed” 220 litre composting tumbler – http://www.tumbleweed.com.au/Composting/220LCompostTumbler.aspx
Here is a picture I found of the tumbleweed composter, you can clearly see the four ‘holes’ on the lid (there”s a lid on each side!) – http://www.rainbarrels.ie/compost-tumbler-pi-868.html?osCsid=mmvc1khr6s6nmls8m5dq7t5ae5
Ah! Thanks so much! I can see from the video and the photo that the holes are precisely where I’ll put mine — on the “ends”. The difference in the “Tumbleweed CompostTumbler” and my home-made tumbler is that, if one considers all tumblers to be a “cylinder,” the “Tumbleweed” operates (spins, tumbles) “vertically” and mine will operate “horizontally.” The video doesn’t discuss the problem (or benefit, depending on one’s viewpoint) of excess moisture inside the tumbler that may create “compost tea” that must be drained off. One manufacturer of a “horizontal” design tumbler solves this problem with two “compost tea” drainage holes in the door. See http://www.compostumbler.com/StoreFront/product/original-compostumbler. I will not have any such “door” however; I will have the same sort of screw-on, screw-off “top” as “Tumbleweed” and will drain off any extra water or “compost tea” with ten holes, drilled in a line along the bottom of the barrel, each about 1/4 inch diameter, with a “catch basin” underneath to “catch” any “compost tea.”
Since my compost tumbler drains out the liquid from the lids, especially in the rain, I simply collect the compost tea by placing a plastic garbage can lid (the thick solid ones) underneath it, works well!
If you exclude rain water, how much liquid typically drains from your tumbler? That is, how much water does your compost accumulate on its own? Does warm weather cause much or any of it to evaporate through the circulation holes?
Im not sure because my tumbler compost bin sits out in the open, it would depend on the water content of your composting materials.
Thank you!!! It sounds like I was going the wrong way with adding straw and increasing carbon. You mentioned low nitrogen for sheep manure and thus low temp, so if the pile with the sheep manure has already decomposed quite a bit is it to late to add things with more nitrogen ? Would it be better to start over with a new pile of more of a mix of ingredients to get the hotter temps of between 131-170 and to use this current pile as a manure amendment rather than compost? Or can I add more ingredients now?
Thank you,
Tina
You can add more nitrogen rich materials now.
“Compost Starter” question.
Many university extension service offices say that all living things have the necessary bacteria to cause decomposition.
However, the primary components for my compost tumbler will be two: wood shavings and coffee grounds, and neither of these seems particularly endowed with bacteria.
Where I live, there are few chicken farms but many horse stables.
Should I expect any more success (i.e., progress in composting) by adding chicken or horse manure? If so, how much if my barrel is 58 gallons (220 liters) and I put into it, at one time, all ingredients?
Also, how full should I fill my tumbler by volume? one-third? one-half? two-thirds?
“Variety is the spice of life…” and is essential to a good compost too! Manure would be more like a third ingredient, which will be better. I’ve alreay mentioned the compost activators/starters in step 1 of the instructions.
When using a tumble bin, I aim to fill it almost all the way to the top, usually about 75% full all at once, you need to leave enough space for it to be able to tumble and mix around.
Outstanding. Thank you for the guidance.
I just got for free for my compost tumbler about 250 pounds of chicken manure from a man who grows chickens for the eggs he sells.
Some of it is “fresh” but most of it is “old” — that is, we dug it up with a shovel from a heavy, dense pile, parts of which smelled quite bad.
For “bacteria activation” in my compost tumbler, I had thought such “fresh chicken manure” (that I get FREE) was supposed to be superior to
— “Black Hen Composted Chicken Manure” — described at http://blackkow.com/_html/otherproducts.htm — (20 pound bag costs $8)
or
— “Black Kow Composted Cow Manure” — described at http://blackkow.com/_html/howitsmade.htm — (50 pound bag costs $5).
(I presume that anything composted has less bacteria than the raw materials that created that compost because it has gone through a “hot” process that killed certain valuable bacterias.)
I e-mailed the Black Kow people about this and got the answer below, which seems contrary to what I’ve read on the Internet.
I’d appreciate any reaction to the statements from Black Kow.
If you were me, would you use for a tumbler composter “activator” FRESH chicken manure, COMPOSTED chicken manure, or COMPOSTED cow manure?
Thanks.
~~~~~~~~~~
Dear Jock:
[. . .]
Chicken manure will supply nitrogen to the compost, but not a lot of bacteria. A bag of Black Kow cow manure would be a great source of bacteria.
[. . .]
Fresh manure will contain a lot of good bacteria but also a lot of bad bacteria that could cause odors if not composted properly.
[. . .]
Cathy A. See
http://www.BlackKow.com
http://www.DynamitePlantFood.com
———-
Black Gold Compost Co.
P.O. Box 190
Oxford, Florida 34484
~~~~~~~~~~
Today I received a followup e-mail (below) from Ms. See at Black Gold Compost Co. Is her statement about “good” and “bad” bacteria for composting correct?
~~~~~~~~~~
Dear Jock,
Fresh manure will have more bad bacteria since it is not composted.
By the time we compost the product and bag it, the bacteria has been killed.
The product composts at such a high temperature that it kills the bacteria and weed seeds in it.
~~~~~~~~~~
I started my hot compost BEFORE finding this site. I have included layers of rich dark soil between my green and brown layers. The soil had many beautifully large earth worms. Am I going to cook them or will they retire gleefully to the bottom of the heap as the temperature increases?
Chris
Hi Chris, I’m guessing that if earthworms can rise to the surface when the barometric pressure drops (signalling rain) so they don’t drown, they would hopefully similarly respond to increasing temperatures and burrow down into the cooler soil. This is only speculation on my part!
I am calculating the carbon to nitrogen ration of composting cardboard and coffee grounds. I come up with .54:1. Does this mean .54kg of cardboard for every 1 kg of coffee grounds? Is their a volume formula out there and not a weight formula? thanks for the quick reply.
Basically, if you’re working with volume, to simplify things, aim to use 1/3 green/nitrogen containing materials and 2/3 dry carbon materials. In other words, one bucket of nitrogenous material to two buckets of dry carboniferous material.
For example, cardboard has a C:N ratio of 350:1, and coffee grounds have a C:N ratio of 20:1.
If you want to work it out mathematically, you need to take into account the moisture content too, which complicates things. I found an online C:N ratio calculator at http://www.klickitatcounty.org/solidwaste/fileshtml/organics/compostCalc.htm and using your ingredients, with a simple 2:1 of cardboard to coffee, the calculated C:N ratio was 40:1, which is still ok, the fact is they rate coffee as 13:1, while my sources ghave it at 20:1, resulting in a final ratio of 41:1. Really, there is a lot of variation between materials, so it’s not exact. This example just shows how the ‘rule of thumb’ of two buckets dry : one bucket green can be fairly accurate.
thanks for the quick reply. that makes sense. Would the 2 buckets brown 1 bucket green work for leaves, too even though leaves have a c:n ratio of 60 to 80:1? I have also read 2 greens to 1 brown. anyway, thanks for the reply.
on the previious post, I would be composting coffee grounds with leaves.
I am investigating setting up a hot composting unit to take the grass cuttings from a large garden (3 Acres) Would a hot composting unit 2.5 meters square and circa 1 meter high be too big.
If you can turn it easily, then it’s not too big, otherwise make several heaps of a manageable size.
If you turned it with a front-end loader, it would be very easy! That’s how they turn hot compost on a commecial scale!
I am composting shredded leaves and poultry manure. when i plug in 1 cubic foot of poultry manure to 20 cubinc feet of shredded leaves into the compost calculator the computer says 1 part poultry manure and 20 parts leaves and am only getting a 23:1 carbon nitrogen ratio. so this means 1 bucket of poultry manure to 20 buckets of shredded leaves, seems like too much carbon. any clarification would be nice, thanks
What a great post. I started my pile 4 days ago but realized I seriously underestimated my horse manure so the pile was too small. However, I still added urine to activate the pile. So 3 days ago, I picked up some more horse manure and added it to the pile- layering- with more straw (aged straw) and leaves. I am not sure that my pile is big enough since of course the laws of physics do not allow for exact blocking of the pile and it often settled and slipped during the process. So I am really unsure if my volume is correct. Also, I live in New Mexico and we have had a really cold winter these past few weeks so the poop was cold, the leaves are a bit wet, and the straw was cold. I took the pile’s temperature with my 20″ thermometer today and yesterday- it remains at 32 degrees F. Am I doing something wrong? Is it supposed to read around the “hot” temperatures during the first, second, and third days?
Thank you so much,
Adrienne
If temperatures stay low any heat is immediately lost and the pile does not cook, heat up enough. Wait until you have warmer temperatures and in no time you will have compost.
Don’t forget you can add all of your kitchen waste too and I highly recommend it. Stirring a pile will also help speed up the process of turning it into great soil.
I love composting.
One more thing: Everyone can continue to add to their compost pile, bin or whatever throughout the winter. There is no reason to not continue just because it gets cold. (Extremely cold climates are an exception.)
Julie never let us know if she got her pile composted in 18 days or how long it ended up taking 🙁 Anyone finding they can do it in 18 days?
I helped a friend build a hot compost pile when we first learned about it, and it completed in exactly 18 days, that’s why I wrote the article!
Mind you, we ended up with a cubic metre of compost, which was a lot for a tiny courtyard!
Great write up, I’ve trawled through many a site detailing composting but none have outlined it in such step by step detail and known pitfalls as yours. Thanks!
Thanks for the article! I read through almost all of the comments and I didn’t see anything about when the compost can be used. Most of the articles I’ve read have mentioned that you should let your compost “cure” after it finishes otherwise it can burn the plants, and I’m wondering if you have advice on that.
I’m in cold Minnesota and despite the 10 degree weather my pile is already 80 degrees, 3 days after putting it together! It’s getting pretty smelly though, so I’m guessing I need to add some more straw to my pile, and that might cool it off quite a bit. Oh well, not too bad for this time of year!
The compost is ready to use as soon as it’s finished, in 18 days from when you first construct your hot compost heap! All properly made compost will not burn plants and should not require any curing process. I can only imagine that if a compost uses a lot of really ‘hot’ manures that haven’t broken down properly, it would be like adding the manure straight to the plant, and some nmanures will burn plants. You do’y have to worry about this at all. Properly made compost is gentle on plants, you can plant seeds and seedlings into it without any concerns.
Is there any way to “supercharge” your compost before putting it out into the field? Any value to adding biochar, urea, or anhydrous to the process? If adding compost to alkaline soils, ph 8.0, is there a process to make your compost slightly acidic? Thanks for all the good work.
You’re welcome!
No need to do anything to your compost, it’s already “supercharged” with life, it’s packed with lots beneficial living organisms which will enrich the soil and help your plants grow, and compost contains lots of nutrients in natural concentrations or levels that won’t burn your plant’s roots.
If you add any chemical fertilizers such as Urea or Anhydrous Ammonia directly to the finished compost (or even into your soil) you’ll kill all the life in the compost (or your soil), which kind of defeats the purpose of using compost and gardening organically in the first place.
Fast/hot composting creates a slightly alkaline compost, slow compost creates a slightly acidic compost. If you want to make the soil acidic, don’t mess with the compost, just use plenty of mulch over the soil surface which will slowly break down, and if you really want it very acidic, for growing blueberries for example, mulch heavily with pine needles around the plants.
Compost works on its own and doesn’t need biochar either. Just dig you compost into your soil or place it on the soil surface, but under a thick layer of mulch so the soil life can get to work and the nutrients can leech into the soil.
Keeping it simple really is the best way to use compost!
Thanks
Hi, I have just found this site, brilliant advice! I have a hot compost heap on the go now, I am not particularly worried about it taking 18 days, as I can’t gather the materials to replenish in 18 days either. So my question is, will my pile naturally cool down as it becomes ‘ready’ (or as the nitrogen runs out)? Or can i keep it hot by adding more nitrogen periodically and is there any benifit to this? Is there a definitive way to be sure that the composting process is ‘over’? Thanks for the advice! Jon
Hi Jon,
There is no need to gather more materials to ‘replenish’ unless something goes wrong, most of the time, once the compost heap is built, nothing else needs to be added, it only needs to be turned as described, and when it cools down after the 18 days, it will be ready. There is no benefit in keeping it running hot any longer, when it’s ready the bacteria will have used up both carbon and nitrogen, not just nitrogen alone.
After 18 days, you will beyond any doubt know it’s ready, as the compost will be fine, dark, and rich, much finer than any slow/cold compost you’ve ever made.
If, after the 18 days, you want to keep composting, I recommend you leave the completed compost alone and build a second compost heap!
We have a very large manure pile on our acerage, mostly cow, some chicken and goat and lots of hay and straw mixed in. We had to bury our cow in the pile when she died last week (no diseases) and I am wondering how I could go about breaking this all down as quick as possible, it is also winter still here, -20c sometimes at night. I would prefer not to have to disturb her body as it decays or stir up any smells it may give off….can anyone help?
I have a three challenges that could benefit from some group think–not enough nitrogen material, no ready access to water, and cold weather. What I have is plenty of leaves and snow, a trash bag of bunnie poop and carbon bedding, and about a bushel of–what do you call it after worms do their work? It’s great soil, but does it qualify as “nitrogen” for the purposes of hot composting. And if I layer snow in with what I do have, will it melt and make my pile wet enough? I think I’m going to start on Friday, USA. Great site, thanks muchly for keeping it up.
Day 1. Ok, so here…I’ll find a way to post a picture–it is; a layered heap of oak leaves, snow, and grass mixed with bunny poop and worm castings. The down side is the lack of water, and maybe too small a heap. The up side is the high quality nitrogen. I’m not really sure if I got the ratio or thickness of the layers right. It’s supposed to rain/snow and so that could be a good/bad thing. I dithered quite a bit over whether to put it under the wooden fire escape and kind of split the difference by putting it near the border on some rocks and a slight slope. So, if there is too much water it will drain and if not enough…well, that’s the rub…and I guess I can’t post a pict. Maybe on my blog. I’m way to excited about this.
Hi, great article. I am trying my hand at composting and gardening for the first time ever. I bought a plastic bin and have layered dried crushed leaves with kitchen scraps (many of which were already breaking down) and coffee grounds in it. I wet it and mixed it. I rent and hope to move soon which is why I didn’t dig a whole. Will hot composting work this way and should I keep the lid on or off?
Hi Teresa, a compost bin is too small to hot compost in, they can’t hold enough compost, you need to use a cubic metre or more (> 1000 litres) for hot composting.
I have read a lot of your replies stating that a small compost bin cannot be used for hot composting. My question is that I live in Las Vegas and was hoping to utilize the extremely hot summers to start a hot compost bin. The temps this summer have been around 105-115F. Is that enough to be able to hot compost in a 10gal trash bin? I rent and have a fairly small area to work with but I would really like to compost in a way that doesnt attract bugs (specifically roaches). This will be my first attempt at composting. Would cold composting be the best method if I am looking to be able to add kitchen scraps and other materials to the bin regularly?
Hi Michele, hot composting is a biological process that has critical parameters for it to operate correctly. If you need a compost bin around 10 gal in size that will make compost quickly in summer, doesn’t attract pests, and that you can add materials to regularly, then the perfect compost bin for that purpose is a tumble bin composter. The ones that stay horizontal and spin on the long axis, like a jar rolling on its side, are the best to use because they’re the easiest to turn, and if you get one with two compartments, you can have one part filling while the other is full and processing. I’ll have to write an article about these tumble bins soon!
I live in iowa, and right now the highs are in the mid forties, can i still do this or do i need to wait until the summer when its warmer?
If you keep the compost pile covered and keep it running hot it can be done, it’s just easier in warmer weather!
I have grass clippings available at the moment, but not much else. Would it be an option to layer the grass with completed compost rather than laying it with other carbon sources like straw and manure etc?
Layer the grass clippings with newspaper, cardboard, unbleached and unprinted paper, dry leaves, mulched branches and twigs etc. Completed compost layered with grass wont really work, a source of carbon is required.
I do have some cardboard and newspaper, but when I did cardboard a while ago, I found it to be a pain when trying to turnover the compost, so I wasnt going to use it again. Any one have any good methods of the best way to incorporate newpaper and cardboard without spending to much time on it?
Paul, I agree, the problem w/newspaper and cardboard is that it’s time consuming to shred. I tried this w/slight success: at the end of last summer I put a layer of cardboard at the bottom a of drainage ditch by my downspout and then put a layer of leaves on top of it. I didn’t turn it until a couple of weeks ago. It was partially decomposed. Since a lack of ready access to water has been a barrier to me hot composting, I might try putting my hot composting pile in the same ditch. I know that doesn’t really solve your problem, but that’s what I did w/my cardboard! A
The trick with newspaper is to take the sheets and crumple them into tight balls without tearing them up, they help with aeration of the compost this way and provide a source of carbon. Works great with regular cold composting too!
With cardboard, tear it into pieces by hand, it shouldn’t take any longer than 15 minutes to tear uo enough cardboard to have more than enough for a cubic metre sized compost pile.
A word of caution, I wouldn’t use too much corrugated cardboard though, the glue contains boron, which is meant to be only a trace element in the soil, too much is toxic to plants.
To be honest, it’s actually rather strange to suggest that sources of carbon are hard to come by. In a planet filled with carbon based life forms, theyre everywhere around you, all the time. Gather fallen leaves in the autumn/winter period and put them aside for composting. Twigs, branches, dried plant matter and garden prunings work well as a carbon source. Break your materials up into small pieces it if you can use a mulcher, put it on the ground and mow over it, or put in on the ground and chop it up the best you can with a spade.
Remember, the greater the variety of materials that you use, the better the compost. I would seriously discourage the idea of attempting a two ingredient grass and cardboard or grass and newspaper only hot compost. You might as well just spread the lawn clipping straight on your garden if there are no weed seeds in it, or compost the straight lawn clippings in a tumbler style compost bin that you spin around by hand.
If youre going to make the effort to make hot compost, it pays to make the effort to gather a range of ingredients first.
Hi, It is wonderful site to learn small but very useful thing. I am in India, Gujarat, I have plenty of vegetable oils waste. Do I use this as a ingredient of composting green materials?
Hot composting is a system for recycling solid waste material, not liquids like vegetable oil.
Waste vegetable oil is recycled around the world to produce biofuels, it is refined into a diesel fuel replacement for motor vehicles, and also into biofuels used for power generation and heating.
Would it be bad to have the compost heap walled in on 3 sides?
It wouldn’t work as well to use compost bays that wall the heap on three sides when hot composting because with the Berkley hot composting system you need to be able to take all the compost from the outside of the heap first (from all around it) and then pile it up in the new spot to create the centre of the new heap. After that you then put the most composted material that was in the middle of the pile on the outside of the new heap. Essentially, you’re turning the compost heap inside-out! With three sides enclosed you can only access one side of the outside of the compost heap, so you wouldn’t be able to move all the outside material first.
Fantatic information – many thanks !! I have a question I hope you can help with – I am planning on starting a heap and have plenty of carbon (dried leaves) etc and sheep / chicken manure and was wondering if I could dispose of my out of control blackberry bushes in this process as a green nitrogen source ? Would this be effective or suggested to do, or am I putting myself at risk of spreading the bugger further in my garden ? My thoughts were to layer it as a green source alternating with the manure and dried stuff and even pour a bit of urine on it for good measure ?
Many thanks for your advice
The blackberries should break down nicely in a hot composting system, but you’ll need to add extra nitrogen as the blackberries are a fairly low source of nitrogen, they would fit in the category of “Garden waste” with a C:N ratio of 30:1, too low to use on their own as your sole nitrogen source. You’ll need to add lots more nitrogen as the dried leaves you’re using are a fairly high carbon source with a C:N ratio of 60:1.
Many thanks again for your advice – I am very new to this all and find your site excellent. I will take on board what you suggest with the extra nitrogen – might get some extra cow or horse poo in addition to my chicken and lamb stuff I already have from my own farm. My main concern was the blackberry canes mulched up and used in the mix would flourish (being so evasive) instead of breaking down. I would probably suggest that cold composting them would not be advised, but wasnt sure about hot composting. If I can put them to good use like this – then all the better !!!
Many thanks again – great stuff
I love this info! Our school currently uses a method very similar. And have 3 hot composts and a vermicompost. We also use pencil shavings once a week. I was reading your blog re water collection. We are collecting condesation runoff from the air conditioning units.
Thanks for your great insight!
Hi I found your site by pure luck – my husband and I are building a compost heap and I have quite a lot of brown leaves and some green freshly mowed grass. My question is I also have some raw meat that I would like to compost in this heap. I have read your instructions and know to make layers 5cm thick each and to put kitchen waste in the middle. After 4 days when I am moving the heap do I continue to keep the meat/fish in the middle of the heap each time I turn it? I also have prawn heads and shells and the shells of mud crab. As we are in Autumn now I understand I will need to keep the heap covered with a tarp. Would you advise me if I should use the raw meat and seafood in the heap please
If the compost gets hot enough, like it should, you shouldn’t be able to see any of the meat/fish/scraps in the middle, it should have disappeared! Make sure it’s all cut up very fine so it breaks down faster! Make sure you also have enough of a material rich in nitrogen between all the layers, such as manure, blood & bone or something similar, as grass alone as a nitrogen source might not get hot enough.
I admit that I was sceptical about this method of making compost. I am therefore delighted to report that it worked. I did not worry about having a precise carbon-nitrogen ratio mix: most of my raw material (approx. 3 sqm) was grass clippings, with about two months’ worth of kitchen scraps; some garden refuse (twigs, leaves, weeds, and branches cut into small pieces); and some shredded paper. I followed the instructions almost exactly otherwise, except that occasionally the interval between turning the pile exceeded two days. I also watered the pile after turning it each time.
The inside of the pile grew exceedingly hot during the composting process, as expected. I doubt that the white substance that appeared (see earlier posts) is actually “fire blight” – but even if it was, it did no harm, and it disappeared in due course. The pile was typically smelly after having been turned each time, but this smell only lasted a few hours (at most), and was attenuated with watering.
In three weeks, all of the raw materials (except for some twigs, woody roots and bits and pieces of other wooden matter) had turned to compost. The temperature dropped considerably and there was no smell; it was impossible to identify any of the original material. The final stage in the process – from the point where there was still some identifiable grass clippings, leaves and paper, to the point where I only had warm, friable compost – seemed to take place overnight and occurred very late in the process. I noticed only a slight loss of volume overall.
I began using the final product almost immediately. I screened some of it to use as a turf underlay, and used the remainder – including twigs and other matter, all of which I am told will eventually break down – on various garden beds, most of which have a poor soil base. I have no doubt that my plants will thrive.
A few points:
1. The twigs, etc., that do not break down might be profitably re-used in subsequent compost production (ie, if you prefer not to use them on your garden bed).
2. This video (http://www.youtube.com/watch?v=-Jm-c9B2_ew) demonstrates how the heat generated from a small compost pile was able to heat water for 500 hot showers!
3. The regular turning of the heap is very good exercise!
Thankyou for an excellent tutorial.
just read your great article and may apply it a compost heap i have just finished preparing. I am working as a partial teacher here in a district outside of Kathmandu city Nepal. Trying to help the Nepalese people move away from chemical fertilizing back to natural methods. if you know of any permys that want to help out in Nepal send them my address, these people could really use some teachers in this field.
i definetly will be trying out your method on the next heap i build thanks mate
This is the best How-To I have found yet!
A big thank-you; I’ll be sending more people your way for sure.
Theresa
Great site and im keen to try it.
Is it ok to add moss/grass clippings that have been treated with ferrous sulphate? Had a guy come out to look at our lawn as it had been left to its own devices for over a year (We have just bought the place), It was strimmed back and treated with ferrous sulphate as we had more moss than grass!
2 weeks after treatment, we are still raking out the moss and old dead grass i was hoping to use this in some way rather than have to burn or dispose of it as there is quite a lot of stuff (1/2 acre of lawn). Would it be more carbon rich than nitrogen given that its mostly dead?
Would it be suitable to mix the resulting compost with some sand to make a good top dressing for the lawn?
Cheers Neil
Hi Neil, You can definitely compost the moss and grass, the iron sulphate should be fine, it will simply make an iron-rich compost. If the lawn clippings are mostly dry, they will be richer in carbon, you might need to add a bit of nitrogen rich material to help it break down. You can use the compost straight as a lawn top-dressing, add teh sand only if you need better drainage.
Regards
Thanks very much for the reply.
Im trying to get hold of a shredder for some hedge clippings and brambles so once i have that ill get everything pilled up with some fresh grass clippings and see how it goes.
Ill report back, from the ever tropical Northern Ireland!
Hi love the hot composting method but i must admit that i wasnt as diligent in turning the pile for about a week after the first ten days we were bombarded with rain for about 4 days so i had my pile covered with a tarp. When I uncovered the pile i saw mushrooms everywhere so i turned the pile and watered it as usual but the next day a mushroom head was poking out. I wanted to know is ths something that I should be concerned about and what could I improve upon to reduce the amount of mushrooms in the pile. I have also heard of mushroom compost so could the sight of mushrooms be a benefit. My name is Joseph just a beginner composter that is looking for some answers.
The mushrooms are just breaking down the carbon-rich materials in the compost heap. You’re making mushroom compost! If mushrooms are growing, it indicates that the heap has cooled down too much, because mushrooms won’t be growing in a hot compost system that is cooking away at 55-65 degrees Celsius!
Hi! Your information is great!! I have some questions… Can I put manures (horse) straight in the compost pile, or do I have to leave it until it dries before adding to the pile? And is it reliabe to use sawdust for the compost?is it possible that it has some chemical products on it?
Thanks!
Yes, you can add horse manure straight to the compost pile, that’s fine, no need to let it dry. You can also use sawdust in your compost, use thin layers, as long as it’s from natural timber.
Don’t use sawdust from man-made wood products such as particleboard, MDF (medium density fibreboard) or plywood as these contain formaldehyde-based glues which are toxic.
My understanding is that microorganisms are what make a compost pile work, and microorganisms are found in soil. So why don’t you recommend adding soil to the green and brown materials in the compost pile? Thanks.
Hi Bob, in the first step I do mention adding activators such as old compost – this is because compost that is already made is the richest source of composting bacteria.
You can definitely help things along by adding soil if you have a rich, healthy dark humus soil with lots of organic matter in it that is packed with soil life.
Unfortunately some soils are quite lifeless, damaged severely and quite sterile. The type of soil really matters.
If you don’t manage to inoculate your compost pile with premade compost or healthy soil, the ever-present microorganisms still somehow find their way into the compost heap!
Hi Blackthorn,
I’ve been making compost off and on for years, using various methods, but I don’t think I’ve ever succeeded in making a proper hot compost heap, so I’m now quite excited at having a go at this, having seen the proper way to do it.
I have a slight worry though. I haven’t seen any mention (I don’t think) of vermin (typically rats), which can often be a problem with cold composting, even using a bin of some sort. I would have thought an open heap would be more prone to vermin, or does the high-temperature keep them at bay?
With thanks and best wishes,
Mike (from the UK, where the “summers” seem to have been getting colder and wetter in recent years!).
Hi Mike, at the temperatures of hot composting, any rats or any other vermin that get into the heap when you first build it will be cooked, decomposed and thoroughly composted – you’ll be lucky to find anything but the shiny clean bones!
Thank you Blackthorn! 🙂
Always welcome!
Hello again, I have now made about a dozen hot compost piles, and never had one fail, winter or summer. I use used pet bedding mixed with whatever green I have, it’s so easy and an amazing process! Excellent site. My question is, I want to heat my polytunnel over this winter with a succession of hot compost heaps, but usually my pile is about 3m cubed, so I want to get this down to about a metre. Is there a way I can make my piles more ‘efficient’ by using different materials so I can get the volume down? Thanks for your help (:
Great to hear your success with hot composting, thanks for sharing! No need to make your compost heap smaller, you can tap into the heat of the bigger pile and direct it to your polytunnel enclosure. If you do a search on the web you’ll find instructions for building hot compost water heaters that can be used for providing hot showers, etc. They just use a long heavy duty hose coiled under the compost heap. Instead of showering with the hot water you can have it circulating through a long copper pipe or a copper coil (which radiates out the heat) inside your polytunnel enclosure, and connects back to the hose as a big loop, like a solar hot water heater.
Found this interesting compilation of “on-farm composting methods” of which the Berkeley system is one:
http://www.fao.org/organicag/doc/on_farm_comp_methods.pdf
Regards,
Mike
High Blackthorn, what a great site, I love it.. I’m a long time organic gardener and have cold composted for many years. I have a 2 bay set up where I build up the heap progressively using any waste I can get from the garden and kitchen inter-layered with soil. When the bay is full I move it top to bottom into the 2nd bay, aerating it and moving the oldest compost to the top. I get 3 bay-fulls (about 3 cu.mtrs) of good quality compost a year from the system and I am able to use it continuously as the second bay continues to break down. Its worked well but I really like the sound of the hot composting process and plan to start my first heap. I can get an almost limitless supply of wood chips from the local tip (accumulated waste from arborists), so I was thinking of using this as my carbon content and chicken manure as nitrogen. The woodchips are fairly course and I am wondering if this will work OK. I am using a lot of my organic waste from the kitchen and garden in my wicking worm beds these days, so there is less than there used to be for the compost heap.
Hi John, I really doubt that new coarse wood chips would lend themselves to hot composting as the only carbon source, the bacteria would have trouble accessing the carbon as it’s locked up in the wood and there is not much surface area for the bacteria to act on to start breaking down the material. My guess is that the heap would starve of carbon very quickly.
Also, making a two ingredient hot compost is something I don’t recommend, the finished product is only as good as the materials you put into it, the more the better for a more balanced compost with a wider range of minerals and nutrients.
You could re-mulch the wood chips to finer pieces and give it a try, but the end result won’t exactly be a fantastic compost unless you add more ingredients in there.
Many thanks for the feedback. It is appreciated, however I do want to make a couple of points.
First, I have been using woodchips in my cold compost for years without problems breaking them down, they are crushed in the chipping process which splinters them and increases surface area significantly.
Second, I have been persuaded recently that the main benefit of compost is that it supplies food for the soil biology. It is said that the diverse microorganism population of the soil breaks it down and provides nutrients to the plant in a form easily assimilated by them.
Humus is probably the most concentrated form of food suitable for microorganisms, hence my interest in hot composting, but in nature cold composting seems to be the way microorganisms are naturally fed. It seems to me that the origin of the compost is not so important as the micro-organisms attracted by it.
In my worm farms (built into raised self watering wicking beds) I feed the microorganisms with finely chopped kitchen and garden waste (A large handfull every 2 days). In 4 days the waste has been largely broken down by microorganisms with the help of composting worms. Burrowing worms distribute the microorganisms and their food into the plant growing area of the wicking bed).
A good article on this and related subjects can be found at:-
http://www.theatlantic.com/health/archive/2013/06/healthy-soil-bacteria-healthy-people/276710/
My blog on Wicking Worm Beds is at http://www.jas49580.blogspot.com.au
Incidentally, I have used your list of C:N ratios in my blog, I hope you don’t mind.
Hi John, excellent points, thanks for sharing! If the woodchips are not large hard chunks on wood, it’s fine. I use a chipper type mulching machine with a large slow turning cutting wheel and feed heavy tree branches through it, which I then cold compost like yourself.
You’re welcome to use my list of compost materials C:N ratios, as long as you cite the source, either the site http://deepgreenpermaculture.com/ or the page http://deepgreenpermaculture.com/diy-instructions/hot-compost-composting-in-18-days/ as a link.
You’ve got some interesting articles on your blog about one of my favourite subjects – worm farms, I’m looking forward to reading them!
Thanks Blackthorn, The link to this page went in well before the C:N list. They are both in my blog on Organic Gardening, and the list is in the article on “Compost” (What else?).
You can access them through a link in Wicking Worm Beds if you wish. Thanks again for your great blog, and the use of your C:N list. I am sure my blog visitors will get a lot out of them both.
You’re welcome!
Hi, great article. I am preparing a aerobic compost of mixing with 60% paunch (21:1), 20% wood chips (probably 226:1 or 400:1) and 20% of wood ash (25:1) for commercial purpose in winter season. Today (1st day) I recorded temp is 22C only. Was my mixing ratio wrong? If wrong, how to correct them now? Its open, no cover and rainy. pls advise. Regards, Jakir
Way too much wood ash, that would be very highly alkaline! Wood ash is only meant to be used in small amounts, 1/5 is way too much. Less wood ash, perhaps a greater variety of materials. What exactly is paunch, is that animal offal?
Hi, Thanks. Yes that is cow paunch. since that amount of ash is already in mix, so could I add some paunch to increase temp as temp is still low? I like to achieve a C:N ratio of 30:1. Pls advise accordingly. I did not found any weblink that help to calculate C:N of paunch.
Even though offal is high in nitrogen, it’s strongly bound in proteins, and it’s not very fine in size to have a large surface area. You need a source of nitrogen that is more accessible to bacteria to get the whole thing started, such as manure, or blood and bone, etc. Most often, meat is added to the centre of the heap in a small amount, in the form of road kill, bones with meat still on them etc. In this position, where the heat is most intense, the meat is completely broken down. Wood chips and meat is not a workable recipe for hot composting, it’s a way of composting meat scraps slowly in pits in the ground, which is the way farmers dispose of dead livestock, they dig a pit with a front-end loader, fill it with sawdust, put in the animal carcass, cover it with sawdust, then bury it with soil. The nutrients are returned to the soil slowly that way.
Thanks for the ideas and techniques under discussion. I make a lot of compost, using mainly the neighbours’ lawn clipping plus leaves, wee, chook litter and the odd lucky bag of horse manure. I scored a lot of “aggie pipe’, a ribbed perforated black plastic rigid tube that greatly speeds up composting. I just coil it in the Dalek-shaped compost bins (!) and use generously through the big heap. Compost near the aggie pipe matures sooner, I assume because of the oxygen it provides, and also the housing for worms. I highly recommend introducing aggie pipe through your compost, particularly if you have a bad back, as turning is obviated and moving the mature compost is easier when you extract these air tubes.
Thanks Marion, that’s a fantastic tip, really love it, simple and effective, I’ve got to try that in my compost bins!
That’s a great tip Marion. I have heard that compost aerators, which are usually a pipe positioned vertically in the centre of the compost, will cool the pile down. Does your method avoid this?
I’m guessing it wouldn’t cool the pile down because the centre cab still retail heat, while the air passes around the sides.
Great read! I have been a cold composter for years but I am how moving into hot in order to try to heat water for a shower! I have read other sites about the process but I am still curIous on how to attain the “hot” decomposition but have my system last for longer than 18 days. Also I am working in the tropics of Thailand if anyone has any recommendations for systems or adaptations. Cheers!
Thank you very much for such an enlightening explanation on how to hot compost. I want to let you know that I have a successful result from following your instructions. Although the size of my pile never quite reach 1.5 as required, still the core temperature heated up to around 150-160 F. The pile consisted of straw, dried uncomposted leaves from fall season, grass clippings from lawn, donkey & goat manure ( from a friend), garden weeds, kitchen waste. I used pee & some old garden compost to activate it. I am harvesting the compost today, it looks like a rich, dark brown heap.
Excellent results, and good to see that you’ve used a nice mix of materials too! Well done!
I need to know the c:n ratio for fronds from palm oil trees, is it similar to coco palm trees? So far I only get different conflicting figures. Apperciate the help.
From Jen in Malaysia.
If they palm fronds that naturally fall to the ground, they would be dry, no green colour in them, they will be mainly carbon.
Ok, noted and thanks. Have used your technique for past 6 months using different carbon sources and vareity of palm oil fronds. We add compost activator, liquified 20 litres to every heap. Compost activator has anti oudour and EM additive to it. For each heap, the finished dry weight is approx 870kgs. We are doing 6 batches per day for use in our 2,100 acre plot of oil palm, young and old trees. No chemical fertiliser as far as possible since plantation is beside national park reserve.
How do we post you pictures of our production using your method?
You have contributed a lot to us in terms of knowledge and tech support.
Hi there, can you please explain if the compost got too hot and you get “fire blight” mould, does that harm the compost to be used when it’s ready, or do I have to discard the whole heap of compost?
Thanks.
If the temperatures over 65 degrees Celsius you get fire blight which is an anaerobic bacteria, to remedy add some carbon rich materials and turn the compost to get more air into it to and cool it down. Then continue turning as per the procedure.
Since the 90s I’ve used a modified Berkeley method that virtually eliminates turning more than one time.
With a ground base of 1/2 inch diameter brush, cut to 8-12 inch lengths approximately 6 to 8 inches thick, I made a series of alternating layers of first high carbon about 2-4 inches, topped with 1-2 inches of high nitrogen material, or add ammonium sulphate or urea sprinkled on.
Repeating this to the 3 foot high point, I add another 2-4 inches of short brush and then more C and N layers up to 6 feet high. In higher levels I mix the brush into the “C” layer. The turning is eliminated since air easily flows through the pile from the heat.
To slow the air flow I top the pile with soil or fine compost material. When finished building the pile I soak it well with water, and tromp it down if the material is to “fluffy.”
This produces top grade soil in two to three weeks.
For the outer material that does not get hot I simply screen it out and add to the next pile build. I’ve produced hundreds of Cubic yards of very fertile soil this way. It sells for top dollar, and makes a garden like you need to see to believe.
Plants growing in this soil are disease and parasite bug resistant and I use zero pesticides, and zero fertilizer for lush, large plants and vegetable yields.
Hi, I’m sorry I don’t understand what is Brush cut. I’m really interested in your method.
Hi BrisMatt, I’ve edited the previous reader’s comment for clarity, it now reads “1/2 inch diameter brush, cut to 8-12 inch lengths ” – that single comma makes all the difference. As you’ve seen, I’ve also edited your comment to keep the discussion public!
Hi Angelo, Thank you for editing. However I still don’t know what the brush looks like. It still doesn’t make sense to me. WRT to the email address, I have used a disposable one whereby I can delete that address once I get a reply from ClaudeA.
Hi BrisMatt, ‘brush’ is just another word for ‘brushwood’, basically it’s just wood of twigs and branches that have been cut or broken off. Hope this helps!
Hi Claude, sounds like an interesting approach to composting, but how do you separate the cold composted outside material that will still have active weed seeds in it from the hot composted interior compost where any weed seeds would be deactivated?
I should point out that the purpose of turning the compost is not only to get air unto the mix, but to turn every part through the hot core of the heap to break everything down – pathogens, weed seeds, etc.
Thanks for the great suggestion!
Hello Claude, I’m really interested in this method of yours. If you dont mind, can you also send me some pix like what you did for BrisMatt?
I did hot composting some time ago but gave up just because I cant turn it regularly. I am a full time worker and by the time I get home I have very little time and energy to spare for turning the compost. This method of yours would really help me a lot. Thanks.
Thank you, Angelo!
Being a farm boy, my concept of “weeds” from having generations of family and settings’ experience, is based on the fact that nothing is an unwanted plant – every plant has a beneficial part of the production.
In fact, I purposefully grow “weeds” just for the soil-production process. Jerusalem Artichoke is a noxious “weed” in my gardens, and yet I allow it to grow and multiply wild to use its awesome heavy stalk for part of the branch material in the compost pile.
Every “weed” is welcome to grow and thrive wherever it is not a nuisance, and when it is, or I am ready to build a compost pile, I have a ready supply on material.
I say “every weed,” so I do need to clarify. The only weed I try vainly to eradicate here is clinging burr. But, like all others, it manages to sprout all over from wind, bird and animal tracking, so i simply add all i pull to the compost.
Please re-read my pile-build procedure, Angelo, The outside material is separated out to go into the next pile. I use a horse stable, ten-tine fork, and for larger screening, I have an old wire and spring bed frame that screens out brush and un-digested larger particulates.
If some “weed” seed makes it through, the 100% compost soil of my garden is so giving I merely pull the “weed” out, roots and all with a little tug.
The moisture trapping and awesome nutrient content of the soil produces very heavy yields, and plants grow very late in the season, I pick raspberries to just past frost, and root vegetables keep in the soil all Winter, The rhubarb, mints, parsleys, perennial herbs, garlics, onions, and other biennial and perennial plants thrive here in the Puget Sound winters, and I pick Siberian Kale every month except for those with most days below freezing.
Artichoke grows to seven feet, and each stalk yields up to six hand-sized globes. I sow garlic like one sows a lawn, and the large bulbs crowd each other but with adequate water, the yield is amazing.
Dahlia loves this soil, and since “weeding”: is so easy, they grow without any competition to very large proportion. Ditto Glads and lilies.
The point I’m making is that “weeds” are merely a mental issue, and once their management is put into proper order, become a very beneficial ingredient to a wonderful garden!
Britt, I sent the following to your eMail – Thanks Angelo!:-))
”
I’m happy to share pix with you!
I’ve been meaning to create a bog page with this method, but until this interest here in http://deepgreenpermaculture.com, no one seemed to take notice!
I have numerous pix of various stages of building piles, but it will take some doing to reform them suitable for the blog.
To use a few words meantime, picture tree and bush branch trimming piles where branch limbs are under 1″ in diameter extending on out to the smallest stems and leaves. Cut these into 8 to 12″ lengths with all forked sections cut to the main stem, to make separation from the fi8nished compost easier.
Use this material for the ground layer, and the mid-pile layer, and I add some in finer materials that tend to clump together in thick wads.
The idea is merely to get and keep air flow in the pile, but not too much air, as it will dry the pile and halt the reaction.
The frequent pile-turning is VERY labor-intensive, and the brush adds air to the pile without the turning. It’s that simple.
As for destroying pathogens, one or two days at 140 – 160 degrees Fahrenheit destroys such things as chicken bones, small meat scraps, all finer plant material, and begins attacking the lignin component in woody material. The main source of destroying pathogens is not heat, though. The enzymes and living organisms in the hot compost pile – remember, oxygen is the worst enemy of all pathogens – attack the pathogens with vicious ferocity. Think of a bread mold on steroids.
Again, “weeds” are never an unwelcome part of gardening – every single plant adds a harmonious part to the symphony we gardeners enjoy – nutritious, bug and disease-free, ORGANIC produce!
Hi Claude, I agree with you about the weeds, every plant has a purpose! For us urban gardeners with smaller gardens, sometimes we don’t want an entire garden of lemon balm, hence why I like to use methods that take out unwanted seeds!
Some pathogens, which cannot tolerate high temperatures, are destroyed by heat, they are literally cooked, and yes, the complex compost chemistry does the rest, lots of enzymatic activity breaks everything down, it’s wonderful stuff.
Just curious, using your technique, which is a kind of hybrid hot & cold composting system, does your compost pile reduce in size or volume?
thanks for your great work . your effort is awesome
……
my question is :
can i depend entirely on the material of hot compost to fertilize my farm ?
or , i will need some additives like :
-chemicals 🙁 ammonium sulphate , super phosphate , ……)
-micro & macro elements
-bio vaccines “anti-fungal”
thanks again
Hi Mike, if you use a good variety of ingredients in your compost, it will be more than adequate, considering that’s how trees have naturally grown for the last 370 million years, from composted material on the forest floor, you shouldn’t need to add anything else, especially not chemicals.
If you add chemicals to your compost you’ll most likely mess it up because the chemical fertilizers are simply salts in high concentrations and they kill the microorganisms that make composting possible.
If you need to add a range of micro-nutrients and trace elements to your soil or compost, add rock dust (such as granite dust from rock crushers) or seaweed extract (or just seaweed itself).
Hello Angelo or anyone else who can help…
I followed this hot composting method a couple of weeks ago, but the composting process has not completed and I’m wondering where I went wrong.
I built the pile about 1.5 metres high in a cone shape in a spot that gets a few hours sun (this is at the end of winter in Melbourne, Australia). I used two thirds by volume dry brown materials, and one third green materials. The brown stuff was a mixture of dry leaves, pine needles, some partly decomposed fine wood chips/shavings (left after grinding a tree stump) and some newspaper scrunched into balls. The green materials were grass clippings, chopped up garden waste, some kitchen scraps and commercially packaged animal manure (mostly sheep but also some cow and poultry). To get it going I used some urine, liquid seaweed and mollasses.
I kept the pile moist and loosely covered with black plastic, and diligently turned it every two to two and half days, rebuilding the pile from the outside in.
It started off well – the material changed colour to a dark brown after it had been inside the middle of the heap and starting decomposing, and there was no smell. I didn’t have a thermometer but it seemed pretty hot in the middle initially (eg. after about day 6 it was too hot to put my arm inside the middle). It seemed to be on track until about 13 to 15 days in, when it cooled down but the material was yet to fully compost.
That was about 10 days ago. The heap is now dark brown and coarse in texture, and the individual components are still visible (eg leaves) and the process appears to have stopped. I tested the pH and it’s slightly acidic (6 to 6.5). There are no worms to be seen as yet.
I told my partner the problem was that he wouldn’t oblige with the urine and I had to do it myself with a container, but I don’t think that’s it.
I’m unsure (a) what went wrong (b) what to do from here. I need a whole lot of compost to improve my clay soil, which is poorly structured and low in humus. I’m planning to put in acid-loving plants.
Given this, I am not overly fussed about the coarse texture, but worried that if I use the partly decomposed compost it will draw nitrogen out of the soil.
Should I use it and hope for the best, or try to get it going again with more nitrogenous material?
Any thoughts or advice would be much appreciated!
Hi Sara, it sounds like your compost started off well, but cooled down too early. If the carbon source materials such as leaves are still visible, it would suggest that the compost heap ran out of nitrogen. I would try to get it going again with more nitrogenous material, you can try using ‘blood & bone’ fertilizer along with whatever other nitrogen source you’ll be adding, it’s extremely high in nitrogen. Also, try to make the shape a bit flatter, like a big cube or cylinder, a cone geometrically has the greatest surface area for the least volume, so you end up with too much material exposed and not breaking down. Hope this helps. Give it a go and please tell us how you go.
Most common problem with Compost failures is moisture. Either too much or too little.
Because it went well to start with, i believe again its water. Because the stack got hot steamed and ran out of water.
Sara,
One thing my French double-turn soil amendment grandfather practiced for his 20″ deep garden soil fertility was direct incorporation – turning in raw, uncomposted material to allow the soil’s natural decomposing agents to assimilate the material.
One direct benefit of this is the increase in earth worms feeding on the decomposing material. Where plants are growing in the soil the worms’ wastes are directly captured by the roots, and the health of those plants is exceptional
However, for clayey soil the critical issue is air-flow into the soil. To assure that directly turned-in material gets air, add woody, stemy branchlets that are mainly vertical in the soil and one end is near the surface.
The immediate results is that the soil can sustain some plants, and the long range effect is great, fertile soil in a year or tww, where material is added several times and the soil is naturally turned.
Farmers of staiky plants, lie corn, use this same principle to keep the field soils; organic content up, and maintain disease-free crops.
I have driven the machinery that buries such material – quite an impressive operation!:-))
Now, as for “brown” material that still has the original shape and some of the texture before hot composting, you will discover that this material is actually completely decomposed except for some of the ligins that hold the woody parts together. It is ready to support most all plant roots in this stage, especially when directly turned into the soil. In a year or two it will be finished in breakdown due to soil-borne activities, such as earth worms, fungus and molds, and the myriad of tiny creatures feeding on it.
Hope this experience helps.
Hi there, I like to make hot compost (aerobically) commercially for a large volume, using cow paunch (30:1), wood chips (400:1), wood ash (25:1) and chicken manure (12:1). Pls advise me what would be the ratio of ingredients? Very much appreciated.
If you know the % of water in each of the materials, you can use the Cornell Waste Management Institute’s – “Calculate C/N Ratio For Three Materials” online calculator at http://compost.css.cornell.edu/calc/2.html
I wouldn’t use too much wood ash, it’s highly alkaline!
If you haven’t got all the figures to do the precise mathematics, just stick to the basic formula for working with volume, to simplify things, aim to use 1/3 green/nitrogen containing materials and 2/3 dry carbon materials.
In other words, one part of nitrogenous material to two parts of dry carboniferous material.
In your case, I would try 1 part cow paunch, 1 part chicken manure and 4 parts wood chips. Use only small amounts of wood ash.
Since you only have one main carbon source, the wood chips, the ratios to use also depends on how much of the each of the nitrogenous ingredient (the cow paunch and chicken manure) that you have.
Try these basic ratios on a smaller scale and adjust ratios depending on your availability of materials, and results in composting. If the composting process shows it has too much nitrogen, increase the amounts of wood chips. If it is not getting hot enough or breaking down completely, add your nitrogenous ingredients.
Keep in mind that there is so much variation in the amount of carbon and nitrogen in any one ingredient sourced from different places or even different times, that you can’t calculate this exactly mathematically from the first instance. It’s a matter of experimenting.
Also with your large scale hot composting, will it be in a huge commercial closed vessel or composted on the ground in open air – this will determine how much cow paunch you can use. In open space, outside of an enclosed commercial scale hot composting vessel, you can’t have animal guts exposed to open air, you can only have smaller amounts in the centre of your compost pile when you begin, deeply buried in the core of your compost where it gets the hottest. The size and density of the woodchips will also determine how much paunch you can use, and how effective your carbon source will be. Large chunks of heavy, dense wood will not compost very easily.
My advice, test your ingredients and fine tune the proportions of each material with a smaller heap, then scale up after you can successfully hot compost on a smaller scale.
Super responsE!:-))
Depending on your budget, and with that scale of material it appears substantial, you may want to look into forced draft composting if for no other reason than to lessen the very strong likelihood that with those very fine particulate materials, and especially the entrails, oxygen flow to the innards of any pile will be severely curtailed.
Commercial forced draft composters also speed the production by several magnitudes of scale, producing finished soil in less than two weeks, and for many dairies, in one week or just days. Of course, moisture and temperature are critical factors, as combustion temperature can be reached in a matter of hours.
I’d like to hear of your experiments! Sounds quite interesting.
Great info thank you very much, however, I do have a question regarding the ‘fire blight” comment. When you say “fire blight” do you mean bacterium Erwinia amylovora?
Thank you.
No, it’s not the ‘fire blight’ pathogen Erwinia amylovora that affects apple and pear trees, you can actually use hot composting to destroy plant material infected with the pathogen Erwinia amylovora.
I think what is being referred to as ‘fire blight’ in reference to hot composting is some kind of thermophilic composting bacteria.
thank you for your prompt reply. best regards, jax
I am using a 200 litre compost bin rather than an open pile and am only able to get the temperature up to 37C. I would like some help to get more heat.
I am mixing up the C and N fairly well but maybe I have not enough C because the level of the compost keeps dropping a few inches a day.
Other thoughts I had were:
1) The first items I put in were not cut into very small pieces so maybe are rotting slowly. I am now chopping everything up as much as possible. Could the early larger pieces explain the low temperature?
2) The bin is 90cm high and the circular shape is 70cm in diameter ie much smaller dimensions than the article recommends. Do you think that this smaller capacity explains the temperature not getting any higher?
3) Turning the content of the bin is not easy. I am mixing it up as best I can, but can’t get to the bottom 30 m very easily. Should I consider emptying out by tipping the bin over and put the compost back more evenly mixed.
finally,
4) I am continuing to add materials (both household peelings etc and garden clippings – I am in Wales so am doing the start of autumn clearing of the allotment); do you think the adding of new materials is slowing the whole rotting process? If so, should I start a new compost heap (or buy another bin) and leave the first one to do it’s own thing (turning when needed)?
Many thanks for the helpful article. Definitely got the compost bug!! Even added some urine this morning.
The reason why the instruction specify that the compost pile needs to be of one cubic metre in size or larger (over 1000L) is because you need that much material to reliably reach the required temperatures. We’ve all heard about haystacks catching fire when they start composting, very large amounts of material can generate a lot of heat! A small compost bin, even a large one, simply cannot hold enough material to make a compost heap big enough that will hot compost. I have several compost bins, four 200L bins and a 400L bin for cold composting, and no matter what material I use or how much I fill them, they cannot hot compost.
Not sure why you use a bin, but it may be due to occlusion of air. Also, the finer the source material, the less trapped air – oxygen – there is. You might look into cold composting with a fungus mix for your operation. The fungus destroys all material – seed, bacteria, and lignins, much like hot composting.
Also, if there is enough air-oxygen, and the nitrogen is low, add a little ammonium sulphate of urea, or even blood meal to raise the “N.”
Also, fall leaves clump together in mats that block air flow, and exclude air entrapment. This is one main reason I developed the addition of brushy material and the smaller limbs and branches to allow for air flow. On a cool morning with the sunlight right, one sees a wispy steam rising from the top of a good hot pile with an earth or finished compost topping to partially seal the pile.
Works every time for me.
Thanks to Angelo, this forum promotes one of the nicest composting informations sites online – so, thank you, Angelo!:-))
Thanks Claude for bringing up another method of breaking material down like hot composting, but with a cold composting system.
You can cold compost weeds in an airtight sealed container using the bokashi bin mix, this is a mix of lactobacilli, fungi/yeast, and phototropic bacilli (Lactobacillus casei, Lactobacillus planarum, Lactobacillus fermentum, Lactobacillus delbrueckii, Bacillus subtilis, Rhodopseudomonas palustris, Saccharomyces cervisiae) which is used to ferment food scraps. The fermentation process is very acidic and destroys weeds and weed seed. After two weeks the fermented waste can be added to the compost bin or buried in the soil.
I even found a great technique at the GARDENS FROM GARBAGE website FAQ (http://gardensfromgarbage.org/home/faq_about_bokashi_composting) which describes how to make soil with fermented bokashi material:
“You can make your own “soil factory” in a storage tub: put some good soil on the bottom, add a layer of well-drained fermented food waste, mix well. Cover with a layer of soil and flatten. Cover with plastic or a lid to keep it from getting wet. After about 30 days, it’s ready for use as “good dirt“.
I’ve got to try this myself!
I donate about a day per week to make soil for a community garden in Seattle. The other day one gardener showed me his new experiment with this His hopes were for kitchen wastes, and meat-bone scraps.
I’m not sure how much pathogen reduction earth worm vermiculture does, but I would think that the soil these little creatures produce is full of similar fungi and bacteria. Pathogens are viciously attacked by oxygen-breathing organisms, and worms promote oxygen breathing flora and fauna, so vermiculture may be a viable procedure to produce safer material to add to the hot pile, or maybe use as is, which I know many do.
I’d like to learn about more ways to produce soil from different raw feed stocks. Each has specific nutrients that combine to provide plants with both health and disease / parasite resistance.
In my use of 100% compost for the garden growing medium, I see very little parasite and almost no disease, opposed to plants growing in the native soil. But I have not made an effort to determine what causes this.
I do have some slug issues, but the rough texture of the compost turns most away, and for the persistent ones I scatter diatomaceous earth around the few plants slugs insist on messing with. They do not cross the DE at all, and where it is on the plants they also stay off there.
Has anyone here experienced composting plywood, or other similar glued-together wood construction material? I was given quite a bit of thin plywood which is separating at the glue joint.
After reducing the size to about 12″ square or smaller, I have built a pile in layers of recent yard wastes – acorns, leaves and some composted leaves of last year, cardboard and paper, and hot material from the active compost pile.
With a few pails of water added to these layers and topped with active, hot compost, I’m hoping the Douglas Fir plywood will decompose by next Spring. I wonder if I should have added a commercial form of nitrogen, such as urea or ammonium sulphate to help the large amount of wood to break down.
If anyone has experience with similar material your advice is appreciated. Also, Angelo, did you see any mention of the fungus being used for woody material breakdown? I’ve seen piles of wood chips where fungus permeated the pile and rendered the wood into a softened form, but not into a completed soil-quality material.
Thanks:-))
Hi Claude,
There have been studies on composting of plywood.
Wiltcher, D., et.al., “Composting of Phenolic-bonded Softwood Plywood Waste”, Forest Products Journal, Vol. 50, No. 10, October 2000
(http://www.thefreelibrary.com/COMPOSTING+OF+PHENOLIC-BONDED+SOFTWOOD+PLYWOOD+WASTE.-a071325028)
Leungprasert, S. and L. Otten, “Fate of Formaldehyde in MDF Sawdust during MSW Composting”, University of Guelph, Guelph Ontario
(http://infohouse.p2ric.org/ref/12/11529.pdf)
The glue in plywood is urea-formaldehyde glue, which is toxic on account of the formaldehyde it contains. From the studies it looks like it takes 180 days (i.e. half a year) for the majority of the formaldehyde to break down in the first study. In the second study, 90% of the formaldehyde is broken down after 10 days of hot composting. It appears that it’s not completely broken down and considering formaldehyde is a known carcinogen, I would simply find less toxic materials to grow food with! Its not worth poisoning your soil for, considxering carbon based materials are everywhere, autumn leaves, fallen branches, newspapers, etc.
Fungi break down wood into soil, that’s their role in Nature, you can use shitake mushrooms to turn hardwood logs into lots of mushrooms and mushroom compost.
“Need optimum temperature of 55-65 degrees Celsius. At temperatures over 65 degrees Celsius a white mould spreads through the compost, which is actuallyfire blight, an anaerobic bacteria. Temperature peaks at 6-8 days and gradually cools down by day 18.”
Hello there from South Australia, I have made a pile at our school, it has been cooking for 7 days now and when tested today and the day before it was 75 degrees and today probably about 65.I had not measure the temp before this. Can it get too hot? And this white mould, is that a good thing or a bad thing. It has lots in the middle of the pile. I assume if I turn the pile now…it will heat up again and that is what you want? I have been told just to leave it. Perhaps add a little more water? It has a mix of roo poo, straw, blood and bone, lawn clippings and Lucerne hay. It gets incredibly hot, great to show the kids at school! Would appreciate advice, thankyou.
Hi Janelle, your hot compost is getting too hot! If it gets way too hot some of the bacteria that are more comfortable living at the lower temperature ranges get killed off I believe. Only add water if it needs it to maintain the correct moisture level. Please keep following the instructions, it’s still on track, keep turning it every second day, it will help cool it down, and you should have perfect hot compost by day 18. Please let us know how it goes!
Hi, I followed your hot composting instructions but the heap has cooled down now and is just warm. I can’t find blood and bone, I only could find blood pellets and these have not made any difference. Is there any other other quick fix to warm it up? It was going so well, it is covered as the weather is cold here in France. Best regards Katharine
Hi Katherine, you can add ANY rich nitrogen source to make the compost heap heat up again. Any animal manure will do just fine, as will human urine!
Hi there
Firstly this is an amazing source of information and inspiration, thank you.
Secondly I am a total novice and have just started my first compost site. I am also awful when it comes to maths. So I was hoping you could help me.
I have an abundance of the following;
Rabbit poo and wee, mixed with sawdust.
Chicken poo
Grass cuttings
Used organic compost (used for last seasons veg growing)
Kitchen waste
Butterfly bush trimming
Willow trimmings
Fallen leaves
I can also access horse manure easily.
Would you be able to give me a rough ratio in percentages? Hope that made sense!.
Again, thank you so much for building this resource. I used to be a secondary teacher and from this point of view you are excellent at communicating information that is accessible to a wide range of abilities.
Kind Regards
Claire
Hi Claire, thanks for the nice feedback, you’re welcome!
It’s quite simple – forget the maths, just use the simple formula of 1/3 nitrogenous materials (manure, greens, kitchen scraps) and 2/3 dry carbon materials (old leaves, etc.)
Remember, we’re aiming for a C:N (carbon:nitrogen) ratio of approximately 25-30:1.
Your garden waste (30:1), green wood (25:1) and vegetable scraps (25:1) you mention are already at the right ratio on their own! To make these heat up nice and fast, add chicken manure to these ingredients.
Grass clippings (20:1) which are high in nitrogen need some material high in carbon such as dry leaves (60:1), so mix 1 bucket of grass clippings with two buckets of leaves.
The Rabbit poo and wee, mixed with sawdust is already a blend of nitrogen and carbon rich materials, that’s pretty balanced. If there’s too much sawdust in there, add some of your chicken manure to it to increase the nitrogen content.
That covers all your materials, that should do it!
Hi Blackthorn.
I have started trying out a hot compost heap & have a couple of questions. I have had to create the pile over a cple wks (the space for the pile is about a metre square) due to having the correct materials ready. Will this have made a massive difference and will it still be able together hot. measured the temp 2 days ago it was 30, I then added more layers the next day measured temp again and it was at 40 degrees. It is about 700 cm high now so still going..
With layering, should my carbon (dry layers) be thicker than my nitrogen (green) layers to get the correct carbon: nitrogen ratio or the other way round. Also how thick should my layers be?
Seems to be taking me a lot longer than an hour to create a heap, although I don’t have a shredder so doing it all by hand…
I live in the UK so getting colder here now, I was going to cover with tarpaulin,..should I do this on all sides or is the top and front enough?
Appreciate the help, it is a very exciting process.
Regards,
Sally
Hi Blackthorn
Thanks for the informative site. I would like to share my hot composting experiences with you, although I use a different system that takes a bit longer than 18 days and requires no turning. I live in a very windy part of South Africa, so I’ve made a 1m square chicken wire support and lined the sides (but not the bottom) with heavy-duty black builder’s plastic.
I put garden waste and food scraps into this over a period of a few weeks, adding woody material from a previous compost heap and keeping it moist. I don’t have any manure but I have plenty of leaves, grass cuttings, hedge trimmings and weeds. I usually cut the stalks and big pieces up with pruning shears before adding. I cover it loosely with plastic while the heap is growing and it generates some heat.
When it is full (about 90cm high) I add a thick 30cm layer of grass cuttings mixed with dry leaves, water it well and cover it tightly with black plastic weighed down with stones. It gets extremely hot and gives off steam if I lift the cover and dig down with a trowel. After a matter of days or a few weeks it cools down and turns into good black compost all the way through. The earthworms multiply the longer I leave it.
The time taken varies, depending on the season (we have cold wet winters and hot dry summers – I will time it more exactly in future). I used to turn it occasionally but it didn’t seem to speed things up much, and I’m nearing 70, so it’s a good method for an energetic geriatric. I live in a complex built on clay, so this is a valuable resource for my patch of garden and the others I look after.
Do you think this would work on other continents?
Best wishes, Jackie
Jackie, i’m really glad you shared that. I’m in Ohio at about 41 degrees North, so we experience all four seasons (snow in winter). I will let you know if I try it, but i think it would work in summer.
hi , i am in india and think your explanations are very good.you have taken a lot of effort. can you please answer one question. after we have made the pile and turned it ,can i water it again if i feel it is too dry.will appreciate an answer.. thank you ..
Hi, I had been trying to get my compost to heat up for a couple of months and was getting a bit demoralized. I totally underestimated the amount of nitrogen that I needed to add – or maybe I didn’t realize how much carbon material I had put into the piles.
Anyway, a week ago I added a bag of Blood and Bone (about 5kg) into each compost pile and Voila! Worked like magic.I can’t tell you how excited I was to see the steam pouring off of the piles.
Thanks very much – this is a fantastic website.
Florence
I am Irish and live in Poland. At this moment, I have about 8 large piles of horse bedding that I have been composting since around april. The latest pile is about 2 or 3 cubic metres in volume. I wont turn it because it is a lot of work although I do check it to see if it is hot. Occasionally, I have removed some material from the bottom outer section and even that has been hot. I intend to use the composted material for raised beds. I havent used tarps nor any sheets to retain heat etc but I have used soil. I dug a trench around some of the compost heaps to a spades depth and width and used that soil to form a layer coating on the heaps. It isnt a perfect cover but 80 percentish. Recently, I tried to use a cover comprising of some hay and dried garden grass etc that had been forgotten nearby a ditch and it seems to work. It can help to retain moisture. On some heaps the soil is black but on others the soil is just like greyish soil. Hopefully, I will have about 5 or 6 cubic metres when it is ready to use by september – october.
Hello everyone!
Thanks for this really interesting blog and summary.
I am working for the IUCN as a Marine Biologist on a Resort in Maldives. The situation with the organic waste is quite sad: Every resort and every local island is throwing the entire organic waste into the ocean, which is detrimental for coral reefs. I am looking for a project that eventually also has financial support to find a solution for this. Herein I am looking for opinions, specialists and ideas. The conditions are a bit difficult: high amounts of different organic waste (raw material as well as cooked left overs) (about 500-1000 kg a day), tropical conditions, great limitation of space, smell needs to be minimized. i am looking for a way to turn it into soil rather than bio-gas, because also soil is limited in Maldives. Eventually every resort and local island could start producing a small amount of vegetables and fruits if we would find the right solution.
I am wondering if you would be interested to do some consultation for me or if you have any further contacts that could help me further in this matter.
Thank you, Barbara
Hi, I’m using composing materials e.g; cow paunch (C:N 21:1), Chicken poo (C:N 15:1) and Wood ash (C:N 15:1) to make compost (aerobic, uncovered) commercially in this winter (also raining) in NZ and the proportion ratio was 70% : 15%: 15%, respectively. 4 weeks gone but temperature still low (34C). It ran well in the summer, not in winter. pls advise how to increase heat inside the pile (1.5m high) or any related advise? Thanks in advance
Hello,
I am trying to have a pile of compost for heat. I will be using straw, wood chips, vegtables matter, grass , and urine. My goal is to have a hot pile for as long as possible. So I am asking how long can I keep a pile going at the best possible heat. I am going to try heating my house using water transfer to radistors, for a 6 months. Will I need 2 piles three months each? What will be the best mix. And are these ratios by weight or volume? I would ghuess weight. But I want to hear it said. Thanks , please e-mail me
Making compost is one thing, building a compost powered hot water system is another, and that would be another whole article in itself! If you do an internet search on “hot compost showers” there are a few videos and articles that may be helpful. For a long, slow release of heat that lasts for months it appears that some people have used very large scale anaerobic systems which produce very poor compost because they use only wood chips rather than fast heating aerobic systems like this which use a variety of ingredients and produce a very rich compost.
i have been trying hot composting but something doesnt feel rite. its been over a month but the compost pile is still hot around 140F. The color has changed to blackish brown and smells sweet n earthy. I used sugar cane trash, rapseed trash and banana leaves as carbon source and for nitrogen i used food scraps and cow manure. C:N ration is around 30.1 and i always keep the pile covered with plastic. where am i going wrong? help would be appreciated.
I just have a quick question about manure in a hot compost bin; should the manure be well rotted to start with or fresh? Thanks in advance!
You can use either aged or fresh manure, they both work.
Thank you! I started my hot compost today and I will let you know how it goes
I am now on day 9 of my hot composting but the pile has significantly cooled. When I turned the pile yesterday it was warm and steaming a little in the centre but it wasn’t hot. How do I get it back up to temperature?
Thanks!
As mentioned in the article, if it starts to cool down, you can heat up the compost by adding a handful of blood & bone fertiliser per pitchfork when turning. You can add ANY rich nitrogen source to make the compost heap heat up again. Any animal manure will work.
Do I need to keep the pile wet after Day 1 or just do the scheduled turning?
See the instructions listed under Day 4 – “Ensure that moisture stays constant. Put gloves on and squeeze a handful of the compost materials, should only release one drop of water, or almost drips a drop.”
Hi there,
I’m trying to compost just flowers here in my locality. Here in India we have lots of temples and a lots of flowers are offered there , even some temples generate 10-20 ton every day, and they simply throw it. I’m planning to make compost and colors out of it.
Can you tell what I have to do when I’ll be only composting flowers like Marigold, rose, etc.
And how will I manage the composting ‘coz I’ll be getting 10-20 tonnes of flowers daily!
Suggestions are appreciated 🙂
The flowers have the same C:N ratio as ‘garden waste’ and ‘weeds’ listed in the article, with a ratio around 30:1.
Add a little dry material rich in carbon and you’ll be able to compost it.
Hi just finished my first compost pile and have a lot more material for another one. Can you please tell me how much comfrey should I put in the middle of the pile? I also added vegetable scraps near the middle of the pole as well.
I watered the pile once I finished and am a bit anxious that it may not have soaked through the whole pile – water was running out the bottom but I have used leaves that where on my driveway and some had started rotting already (very long driveway). Should I keep watering the pile each day? I am on day 1 of the 18 day composting system.
Hi Angelo, thanks for your very informative website 🙂
I’ve never had much luck with hot composting, but my recent attempt (following your instructions) got me closer to success than I had before. Like Sara who commented above, I think this time around I had an issue with the compost heap cooling too soon, possibly because the carbon sources (including broken up twigs & woody vines, as well as some newspaper/cardboard) were too large or too imbalanced to the nitrogen that I added (including chook manure, kitchen scraps, fresh grass clippings). It’s been over 18 days but the carbon rich materials still haven’t broken down, the temperature has dropped and a few worms have been moving into the heap.
I’m itching to get this compost into the garden asap so I can get my summer veggies growing, so was hoping for some advice. Do you think it would be better for me to mix a nitrogen rich source (i.e. chicken manure) into the heap and keep it going for another week or so, or do you think it’d be possible to apply the half-broken down (still quite woody) compost along with additional chook manure directly to the garden beds now? The latter option appeals to my impatience, but I’m worried that nitrogen draw down might slow the growth of my summer seedlings. Would you recommend that I be patient and continue the composting above ground, or can I get away with digging it in now?
Thanks!
You’re welcome!
The best way to make any compost is to break up your materials really well. Large chunks of carbon-rich material don’t break down very easily, there is very little surface area for the bacteria to act on. By breaking up materials you increase their surface area which exposes more material for the bacteria to work on.
If you add compost with woody material that is not broken down into your soil, the woody material will continue to break down in your soil, but the bacteria will need to draw the nitrogen out of your soil to compost it, which means your plants won’t get to take up the nitrogen, and suffer from nitrogen deficiency. This phenomenon is called ‘nitrogen draw-down’. Don’t do it, you’ll starve your plants of nitrogen and they won’t grow very well!
Your best option is to use the material again, doing another 18 day hot compost by adding more nitrogen containing material. The idea of using it your incomplete compost as is with lots of woody material in it with chicken manure is not a worthwhile choice because whenever you add chicken manure to your soil you need to wait for a minimum of a week, preferably two weeks, before you planting in the soil, as you can burn the roots of plants and seedlings, and it takes the bacteria time to start acting on the manure to break it down so the nutrients become available to the plant. Plants can’t feed on manure, they feed on the nutrients released from manure by bacteria. Either wait 14 days and still have a problem because the woody material in your soil that won’t all break down, or do another 18 day compost. It’s worth the extra 4 days!
If you’re really feeling lazy, just get a yourself soil sieve, or make one out of wire mesh, and sift your compost to separate all the course material out. Use the fine compost that has broken down in your garden, and put all the coarse material that has not broken down to one side, break it up much finer, and use it in your next compost attempt.
Hope this helps!
Hi Angelo and Em
My own further observations on the hot compost heap that cools too soon:
Following Angelo’s advice about my similar problem and some trial and error, I’ve found that I need a slightly higher proportion of nitrogenous materials to keep the heap hot and complete the process in three to four weeks. (Perhaps this is because some of the carbon-containing materials I’m composting are at the higher end of the C:N ratio). I re-activated my heap that cooled too soon with more manure and lawn clippings, and some blood and bone, and ended up with a fine, high quality compost at the end.
Over a number of heaps, I’ve found that adding a good portion of fresh manure (rather than the dry, powdery, more “composted” stuff) makes a huge difference to the success of the process for me. (I’ve been using fresh sheep manure). In my most recent heap, I used fine, more composted commercially bagged chicken manure and it didn’t work so well. In theory, if the C:N ratio is right the heap should heat up and stay hot as expected, but for some reason in practice the fresh manure seems to get the whole thing hot and going far better for me than without it.
I would reinforce that the other thing that seems to make a big difference is keeping the heap evenly moist. I keep mine loosely covered with black plastic to keep out any heavy rain (to avoid cooling it too much by becoming waterlogged – also a contributor to my heap that cooled too soon), and to keep the moisture and heat in. In a sunny spot with the black plastic on, I’ve found the outside of the pile stays much more moist and composts better than if the heap is open and dries out somewhat on the outside. (I am composting in Melbourne, Australia – the black plastic may be superfluous in warmer and/or more humid climates).
Em – keep at it! The process may require some fine tuning and trial and error until it works best for you and the materials you’re using, but it’s worth it for the lovely fine, rich compost at the end. An alternative to sieving your compost may be to chop up the woodier material (eg woody vines) a bit more with a spade and return it to the heap, depending on how woody it is overall.
Sara
Thank you for this wonderfully explained post, me and my husband started our pile today! This is very educational to us and appreciate it
I have a question, today’s day 3 of my compost and I have notice a little shrinkage, my question is does a little bit of shrinkage suppose to happen?
If your materials are coarse or there are air spaces in the pile then it will settle slightly as the materials break down and the spaces get filled in.
Thank you for your excellent resource.
Just finished sifting the results of my second hot compost pile following your recipe. Beautiful rich material 🙂 Setting up for my next pile. I shred all my materials using a leaf shredder. Is your 1/3 green to 2/3 brown more correct for unshredded materials where the brown has a lot of air spaces in it? Should I be looking more at half green to half brown?
Also I have kitchen waste with some scrunched up paper in it from a cold compost bin with has built up over the past 8 months. I would like to add this to my hot compost as I really need to use everything to add bulk. Do I consider this to be green in my ratio calculations or neutral? That is, layer it in thinly but don’t count it in my green layer to brown layer ratio?
Any suggestions would be very much appreciated.
You’re welcome!
The ratio of 1/3 green to 2/3 brown stays the same whether shredded or unshredded, the brown material may have more air in it, but the green material is just filled with water instead.
If your kitchen waste has a lot of paper in it, as per the ratio just mentioned, then it’s balanced in its C:N ratio, if there’s not much paper, treat it as ‘green’.
Thank you Angelo, appreciate you getting back to me and so quickly too.
The kitchen waste is “green” even though a lot of it is old having been in the cold compost bin for many months?
I think I will need to add some hay to my hot compost to umph up my “brown.” Does it matter if the hay is not certified organic?
Actually just look again at your info and hay is “green”. Sorry! but still interested to see what you reckon about whether it matters if the hay is not organic.
Hot composting can break down a lot of contaminants in composting materials that can be broken down, and the organic matter is capable of binding many contaminants that don’t readily break down, locking them up.
Another question, sorry, should have thought of all this for my first message. My brown is dried leaves, shredded dry sticks, dry bambo leaves and stems. I have more bambo than leaves or sticks. Is this an issue? Is bambo an ok ingredient?
Bamboo is a grass, and it is also a woody material. Woody materials contain lignin, which breaks down to create the most stable humus. Bamboo is a great ingredient to add to your compost if it is chopped up finely or mulched.
Thank you Angelo, it’s so good to have your expert input – my delicious hot compost pile is now doing it’s thing it has a wide range of ingredients including a good mix of shredded bamboo – very exciting! Happy holidays in the garden to you.
I think, it is very short duration of compost making n excellent method.
Activaters- please let me know the names of Activaters easily available in northern India.
You can use the herbs Comfrey and Yarrow as compost activators, and urine works well too!
i have really enjoyed your explaination,thanks…
I there, if I understand well, it means I can use moose poop in that?
Awesome! I’m gonna start collecting a good pile this winter! (It’s easier to stack in winter).
Also, if everything that was once alive can be composted, then that would include my cat’s hair right? He looses a lot everytime I brush him.
So the question is, does cat hair count as “brown”?
Yes, cat hair and human hair can be composted, it’s actually very high in nitrogen so it counts as ‘greens’.
If you brush your cat, collect the hair and hot compost it. Consider what happens in nature, when animals walk around in their natural habitat, they drop their hair. When then moult going from the cool to warm seasons, they lose a lot of hair, which falls to the ground and is broken down along with all the leaves and other plant material.
Please DO NOT use mouse droppings, they may carry hantavirus which causes Hantavirus Pulmonary Syndrome (HPS) in humans, a severe respiratory disease which can be fatal. The disease is spread by breathing in dust that is contaminated with rodent urine or droppings, or through direct contact with rodents or their urine and droppings. It is not worth the risk for the tiny for the tiny amount of nitrogen containing material you would get.
Ah, not Mouse. Moose. We have a land with a bunch of those big fellas and when we go snow shoeing, there’s often those huge pile of Moose poo and sometime it’s still steaming. It makes us both relieved and pissed off because sseeing a Moose is really awesome… except if it decides to charge you. You can never outrun a Moose… ever.
Skidoos are barely fast enough.
My apologies, I quickly read your question after a long day at work and misread moose for mouse! 🙂
Those giant herbivores would generate a lot of manure, so yes, that can definitely be used in your hot compost!
With permaculture one of the design principles (Attitudinal Principles – Everything works both ways) discusses how we can assess something that we perceive as a problem and reframe it so it is something we can gain benefit from – http://deepgreenpermaculture.com/permaculture/permaculture-design-principles/11-attitudinal-principles/
This is one way of utilising a ‘problem’ as a something of benefit!
PS: I’m from Quebec (Canada) where Moose is on our moneeeeey
We have kangaroos here instead, luckily they aren’t found near our urban areas! Our biggest ones, the Red kangaroos, according to national geographic, can reach speeds of over 35 miles (56 km) an hour, and they can cover 25 feet (8 m) in a single leap and can jump 6 feet (1.8 m) high. They can weigh up to 200 lbs (90 kg). They don’t run, they hop, and can jump over fences easily. Moose are definitely scarier though! 🙂
Thanks, I’ll keep you updates on my moose compost then!
Right now, I’m thinking of using moose manure, lots of kitchen scrap (mostly vegerable peels), cat hair, thin cardboard (empty toilet paper rolls), bits of newspaper, green grass (when I’ll have that… Right now it’s as if I’ll never see grass again, ah the harsh winters…) rest of coffee too
Oh, and I have tons of sawdust at hand. I really mean TONS
Hi,
i have recently attempted your hot composting method and have found it very useful and the concept of having compost in 18 days very exciting! today is day four for my compost, and i think i may have added too much green products. i made the pile out of horse manure, a little cow manure, paper, lawn clippings, kitchen scraps and a little garden waste. on turning it today, i have found that it has heated up but…i think it is a bit too wet. i then proceeded to add more dry garden waste. should i just wait a couple of days before adding anything else? and if i should add anything else to increase the carbon, should it only be sawdust as you mentioned?
kind regard
zinette
Was your compost pile really too wet? I’ve described how to test if it is in the Day 4 instructions – “Ensure that moisture stays constant. Put gloves on and squeeze a handful of the compost materials, should only release one drop of water, or almost drips a drop.” In that section I also mention how to fix the problem, which doesn’t involve adding extra material!
If you’ve added some dry material to fix the problem with the pile being too wet, and there is enough nitrogen-rich material, than that’s all you have to do. Just continue following the steps. Hope this helps!
Hi,
I notice that there is mention of methane being released. Do you know what evidence there is for this, how much is released and how it can be reduced?
Regards,
Ray
When the hot composting process takes place, oxygen is required by the aerobic bacteria. In tiny spots here and there within the compost pile where oxygen momentarily is all used up, the process reverts to anaerobic breakdown and this is when methane and nitrous oxide are produced.
This is one reference on the subject:
Jckel, U., Thummes, K. and Kmpfer, P. (2005), Thermophilic methane production and oxidation in compost. FEMS Microbiology Ecology, 52: 175184. doi: 10.1016/j.femsec.2004.11.003 – read article here
A highly aerobic system such as the hot composting system minimises the production of these gases, whereas an purposefully built anaerobic digester designed to capture methane gas as a fuel intentionally maximises methane production.
Let me put this in perspective though – methane is a natural part of the carbon cycle and is produced naturally under conditions of anaerobic decomposition, in swamps, in the breakdown of plant material on forest floors, everywhere where carbon containing material (all living things) break down in the absence of oxygen, including us when we are buried!
There is no issue with natural processes creating methane, it is produced as part of nature’s essential processes of the carbon cycle which perpetuate life. People fussing over flatulent cows are misguided and missing the point. Do we kill all the cows because they have wind??? What we need to take issue with is anthropogenic greenhouse emissions, the release of greenhouse gases through human activity which does NOI sustain life, and which is non-essential, that is the real problem!
Hope this puts the whole issue of greenhouse gases into perspective.
Thank you for the very quick reply.
I totally share your comments regarding the overall picture.
I was curious about the down side, because I feel there is a very considerable up side that seems to be slightly overlooked – unless I have got it wrong. We agree that cold composting drastically reduces the volume of the compost heap over time. This is because the contents are lost as carbon dioxide, water and small amounts of nitrogen gases. The fact that the volume of a hot pile is not reduced in the same way, surely, indicates much reduced losses of CO2 etc.
In addition to retaining much higher levels of carbon and nitrogen the Berkeley method appears to be preferable to cold composting in terms of the net greenhouse gases emitted. Is this how you see it or have I overlooked something?
Regards,
Ray
Yes, that’s right, the hot composting method is a highly aerobic process which does not decrease in volume like cold composting, and loses the least nitrogen and produces the least methane of all the composting methods!
Hi,
I am enthusiast new gardener and to save bucks I tried your idea and gather
1. Straws (brown Material)
2. Goat Pallet (Manure)
3. Kitchen Waste (Green Material)
4. Chicken beat (Manure)
5. Some leaves
And follow the instructions exactly as you mentioned starting from 05th Feb 2015. All was good and accordingly as told in the article but then suddenly heat vanish and all almost cooled down and I can still see all the coarse brown material as is (in kitchen waste I used Peanut shells which are still almost the same nothing broken and goat pallet still round and running like a ball)
Today (5th Mar 2015) it is 30th day. I do not have Thermometer available for now so don’t know the exact temperature but for sure while turning I cannot feel any heat nor can see the smoke and it appear to be cooled down but still I can separate straws, peanut shells, goat pallet etc but no green material can be differentiated. So what to do now? is it ready? or I have to do something like grinding? I do not have garden so I am doing all this on my roof top and I have all the pictures available and can share if you like.
Awaiting for your guidance.
Thanks,
Jawad
I’ve just read through all the comments and it sounds like there was not enough green stuff (nitrogen) to start with… You could try adding a few handfuls of blood and bone or some more high nitrogen manure…. I defer to the experts who I am sure will comment soon but maybe after so many days ‘cool’ it might be too late to bring it back to life…?
It is now almost a week in cool state I do have a bucket of green material available (kitchen scrap) which can create a layer or two so should I add that and give it a try? and should I water all again to made it wet will that help?
If that cannot bring back to life (finished compost) than what alternate options I do have? What can I do with that stuff to make it useful somehow so that it cannot be a complete pile of waste.
Thanking you in anticipation for all the help one can provide.
If the compost heap has cooled right down, it means you did not have enough nitrogen-containing materials to begin with.
It is best to start a new hot compost heap, and you can use your material that is not completely broken down as the carbon-containing material in the new compost heap.
Thanks Angelo, Few more questions just to make sure I do not end up on wrong end.
Following material I need to use to create new heap
1. Brown Material (current compost heap)
2. Cow / Chicken / Goat manure
3. Kitchen scrap / Grass / leaves (Green Material)
4. Water them to made it all wet and do I need to water them again while turning?
5. Anything else to add?
Sorry for asking such basics questions but just to make it successful this time I need to know these.
Sounds good, only water when the instructions guide you to, and follow the steps from the beginning, hopefully it will work this time. Please let me know how you go.
Thanks for your help
I will start again in few days time and for sure will update my findings thanks again
It is now almost a week in cool state – I do have a bucket of green material available (kitchen scrap) which can create a layer or two so should I add that and give it a try? and should I water all again to made it wet will that help?
Hello Angelo,
Thank you for your inspiring and helpful instructions.
We need your advise.
Our compost is on its 17th day.
*The size of our pile is not exactly 1 m3 (about 0,60-0,70m3)
*It smells very good
*The weather temperature is around 8-20 celcius. When it rains we cover the pile.
*We can observe the decomposing process, the colour is getting darker each day but
Its COLD 🙂 On the very first days it was getting hot but somehow the temperature didnt rise again.
*What shall we do now? Do you have any suggestions?
Does it look ready? If the compost has broken down into a really fine, dark mix that smells nice and earthy where you really can’t recognise the original ingredients, that’s what hot compost looks like when it’s completed. It should stay for longer than just one day though.
Thank you for your quick response Angelo. I am sorry 🙂 I should have given you more details about the situation. They started to brake down but we still can recongnise some of them.? We think that the reason is the size of the pile, as I wrote you yesterday it’s less than 1m3. Is it okey to add something more at this point?
It sounds like your compost ran out of nitrogen and cooled down. As per my reply to a similar question earlier to Jawad, “It is best to start a new hot compost heap, and you can use your material that is not completely broken down as the carbon-containing material in the new compost heap.” Just add more nitrogen containing materials and it should work this time around. Try to get that critical size of one cubic metre or more this time though.
Thank you sharing this article
Built my first hot compositing heap just 10 days ago using this 18 day method temp is steady at 55 deg C. it is made up of cardboard leaves, grass clipping and coffee grounds. we did have an issue at day 6 with smell and a decrease in size, which we got from it has too much nitrogen, that we corrected quickly.
It is built in wheel bin that has been modified to compensate for the width restriction. It is a flow through system with a large access port at the bottom for turning. We use a metal rod placed on top of the compost heap to know when it has completely turned ( we see the rod in the bottom ).
We are using this method to make compost but also heat our underground walipini polytunnel in spring this year and hopefully autumn and winter.
I live in the city and have a difficult time in finding enough leaves, weeds, etc. (let alone animal manure)… Anyway, I have finally managed to get a heap of only around 90cm tall. Must I get it up to 1.5 m tall? Also, I forgot to cover the heap and it’s raining quite heavily (I’ve just started creating the heap). What should I do now? Thanks
I love hot composting myself. The best way I have found to get large amounts of material to make a big batch is by bagging by grass clippings mixed with leaves. That combination of fresh clippings with shredded leaves is dynamite in a hot compost pile. Mowing leaves and grass together. It gets hot quickly, it’s free, and as long as the weather isn’t really cold (sub-freezing) it finishes in two weeks every time. Great topic!
I have been cold composting …just because it is convenient to add a small amount of kitchen scraps, straw from the chickens and garden rubbish to a pile every couple of days …can I now incorporate this into a hot compost pile?
Yes you can!
Hello again,
You can see my first question 4-5 comment before.
We have started a new compost pile as you said. At first everything was great and it worked but it cooled down again. I think we couldnt make small enough the ingredients. So, we gave up of hot composting for this time :/
Now, the question is: Can we go on -with this pile- with COLD COMPOSTING? There were limes, lemons, oranges ect…. How can we go on with cold composting? Thank you in advance.
If the hot compost pile cooled down and you want to use the material for cold compost, that should be fine. Cold composting is slow but you can speed it up by turning it every now and then to mix it up. I’ll write an article on cold composting soon!
Okey great! We’re looking forward for your newest article 🙂 Thanks a lot.
Two questions. Can I achieve hot compost with only two materials, horse manure and old slightly rotted mouldy hay? If so, is it a 50/50 ratio? Also, can I get this started when daytime highs are 10 c and lows are around freezing point, or is it just too cold?
With a nitrogen rich and a carbon rich material you can make compost, including hot compost.
As mentioned in the article, the if you don’t want to calculate C:N ratios just aim to use 1/3 Manure and 2/3 dry carbon materials. That means use two buckets of hay for each bucket of horse manure.
Cover it with a plastic tarpaulin sheet if it gets too cold, his will help retain the heat.
I am very confused about hay and straw. You advised Sarah (April 13) to use two buckets of hay for each bucket of horse manure but your chart puts hay into the Nitrogen list and straw in the Brown list. What is the difference between hay and straw?
Hay and straw are quite different. Here’s a good explanation from the US Forage Export council website http://www.usaforage.org/products/straw-vs-hay/
“People unfamiliar with our industry are often confused by the words straw and hay and mistakenly think the terms are interchangeable. Theyre not!
Both straw and hay can be called forage but theres an important distinction between the two.
Straw is a by-product of seed (or grain) production. For example, a farmer who grows wheat will harvest the grain; the dry plant that remains after harvest is straw…
Hay is grown specifically, and its cut before the plant goes to seed. Because the plant pumps nutrients into the seed or grain, hay will have more nutrients than straw…”
Hello, it is Elizabeth again! I understood your reply about hay and straw but I have a field
which every year grows waist high “grass” which my neighbour cut down for his cows – what have I got, grass, hay – and straw stubble? I do not know what was originally sown in the field and I would like to try hot compost. Please clarify, Thanks
That would be hay which is used as animal feed.
Hi,
My moose manure hunting is going quite well (even saw one of those big pooper) and snow is finally melting down. Should be able to have enough material to start my pile soon!
Hey, speaking of snow melting down, can I use my dog’s manure in the pile? Because there’s plenty of it everywhere now. A lot of it is half degradated (or is the right word degraded? Well breaking down anyway). There’s plenty everywhere in my backyard.
Thanks
Hi, you can use any manure in a compost heap and the heat will break it down, but the problem with using dog poo is that it contains lots of nasty pathogens, and the risk to humans is in the collecting and mixing stage of composting, especially if it’s dry the dust can be quite harmful. There’s also the risk that in the turning of the compost that some gets spilled to the side and doesn’t get heated adequately to sterilize it. Safer to use manure from herbivorous (plant-eating) animals. Some people use dedicated worm farms for pet poo only and you can get specially designed ones that sit partly buried in the soil.
Thanks. Luckily for me, the dog manure I grabbed was quite damp from all the melted snow. I think of using the compost from that pile for my flowers and on the spot I’ll eventually plant my blueberrie bushes. There’s not that much dog manure compared to all the rest of my greens
Hi,
Q1. When a compost is done or almost done, does it need to be kept moist (by misting/watering) and ventilated if not used.
Q2. My compost has been fed with various material such as bonemeal, chicken manure, organic NPK fert., egg shell, UCG, tea leaves, kitchen scraps (no meat), etc. When its done, there would be an imbalance in the N, P and K or even the trace minerals. One would be higher than the other. Would it affect the uptake by the plant – caused by too much of this or that?. For example, too much nitrogen affects fruit/flower bearing plants as I understand.
Thanks
Just keep it covered so it doesn’t dry out.
Your compost is a nice mix of ingredients, it should be of very high quality. Your concerns about NPK are more relevant to fertilizer than compost. Compost is not fertilizer, it is actually a soil conditioner which contains nutrients, and it is a living material in a state of ecological balance because it is a habitat for all the microorganisms in it. Even with compost, your soil (and plants) still need some form of fertilizer for bulk nitrogen in spring and autumn, especially if you have heavy feeders such as annual vegetables and citrus trees.
Thanks for your prompt reply, Angelo.
I am trying to make my piles get hot. my piles are 7 feet tall 16 feet wide and 250 feet long. I am using grass clipings, wood chips, leaves and sludge. I have temp probes in the piles as required by my state to keep the pile at 131 degrees and turn 5 times in 15 days. I can get the temp to the mark I need but I can only keep it there for around 5 days. I have a large windrow turner. any suggestions on how to keep the pile going longer? when I turn the pile it cools way down and basically by the time to turn the 3rd time it gets to cold for to long and I have to start all over again
Goodness, that’s commercial scale hot composting! The temperature of 131 degree Fahrenheit = 55 degree Celsius so it’s holding the right temperature, but not long enough.
I have a few questions I need to ask:
What season are you observing this, is the weather warm or cold?
Does it break down into really fine, dark, compost after five days, or are parts of the original ingredients still identifiable?
Is the right moisture level being maintained, how are you doing this, are you using an automated hydrating system, or is it getting too wet and cooling down from excessive rain?
Turning should cause the temperature to rise because it brings new material deep into the compost pile to feed the bacteria and lets more oxygen in. Turning every three days should make the compost pile much hotter than less frequent turning.
If the weather is very cold you might need to make the pile larger to offset the loss of heat from the surface, or are you running the piles at the maximum size for our machine?
Dear Sir, I’m working in Compost making for Muncipal waste. I am really intrested about your hot composting, which can be compost within 18 days. At the moment, one cabine is about 35 cm3 (5.3m x 4m x 1.7m) I used to pile the organic waste, it takes long time to matured. So I would like to follow your suggestion. Turning the pile alternately. It takes 5 to 6 months to mature. The picture shown is my old picture. Now 6 cabin is full and have a plan to do more cabine to place the compost pile. But just keeping waste is not a sollution for me. I need to know how to do fast composting. So I found your hot composting is a good solution. Looking forward to see your kind help. Thank you.
Monu Jyothi Tamang Sr. Technician Solid Waste & Sanitation Environment Division Thimphu Thromde +97517703979
For that quantity of compost you can turn it using a specialized windrow compost turner or you could use a front-end loader to turn it, and it will heat up and produce compost in 18 days.
Great post , at the moment we are trying to get our beds started and as there is lots of really tough grass in clumps it means sometimes we need to dig these clumps out before cutting and covering with cardboard etc, so we have lots of piles of these clumps of matted grass with soil attached they are thrown into the heap to make compost alongside veg peel and grass cuttings and now and then I add a layer of straw to provide more air however the most of the pile is these clumps of grass with attached soil and my question is should I add something else to even the ration a bit .
It seems I am learning in the wrong order! I have just made my 1st compost pile, 4’x4 and about 3-4′ high. Mostly contains weeds, also house veggie/fruit scraps, and some dried leaves as well. I am now concerned about the weeds and seeding them all through my gardens! Have come across your article about hot composting. At first I thought your 30:1 ratio of Carbon:Nitrogen was by volume but I think that is wrong? Looking at your charts, things like veggie scraps and weeds put me right at 25-30:1, right where I need to be? Add in the dried leaves and I should be good? How do you factor in adding shredded newspaper that has such a high C:N? How do you determine volume of what is needed? This is the part I find so confusing. The turning of the pile is the easy part ;).
I’m not sure if I need to load up the whole pile and just take it to my organics section at the local dump and start over with no weeds. I was ok to cold compost and wait till next growing season for it to be ready but the weeds have me significantly concerned. Will hot composting break down the weeds that spread via runners/roots as well??? Thanks for your help.
I should also add I have horse manure/saw dust compost that could be added. I just got it the other day to add to my sandy soil to make my new raised veggie beds. It is 3 yrs old and she figures it is 50/50 manure to sawdust. It came from horse stables.
The C:N ratio of materials is approximately 25-30:1, the actual volume is completely different, because not only do materials C:N ratios differ but greens contain water!
Basically, if youre working with volume, to simplify things, aim to use 1/3 green/nitrogen containing materials and 2/3 dry carbon materials. In other words, one bucket of nitrogenous material to two buckets of dry carboniferous material.
Thanks for your question, this seems to be a common point of confusion when people are working with volumes of materials so I’ve updated the article and added this information, it’s in bright red and bold type so people don’t miss it!
Thanks for the answer. For browns… and sawdust, any woods that can’t be used? Typical woods around here would be cedar, fir, spruce. Cedar is not good I think? Can a bale of peat moss be used? (the bags that have compressed peat moss in them you buy at the plant shops)
I am concerned as I live in the Goulburn Valley au fruit growing area and I seem to have created a compost pile full of ‘fire blight’. The pile is full of white material and was so hot it broke the glass thermometer I had left in the pile! The compost is composed of autumn leaves, fresh grass, old worm juice leachate and lucerne hay. Its day 6 and due to be turned but would I be spreading disease?
As per previous comments “no, its not the fire blight pathogen Erwinia amylovora that affects apple and pear trees, you can actually use hot composting to destroy plant material infected with the pathogen Erwinia amylovora. I think what is being referred to as fire blight in reference to hot composting is some kind of thermophilic composting bacteria.”
The white material that appears when the compost gets too hot (over 65 degrees Celsius) and short of oxygen is actually some form of anaerobic, thermophilic bacteria, I’m unsure of which ones they are by name, I’m not up on the microbiology. They disappear when the temperature drops and other bacteria take over the composting process.
Hi, thanks for the article, will try it soon. However, I do have a question. Can cocopeat be considered ‘brown’ materials and can I mix cow manure with cocopeat as the ‘main materials’? Thank you in advance!
Yes, coco peat is definitely a high carbon material, its C:N ratio is around 80:1 to 110:1 depending on the source. If you mix it with cow manure as your nitrogen source it will create a hot compost.
Thanks for the quick response 🙂
If you don’t mind, I would like to ask some more. Can weeds that had been treated by using herbicides be included in the compost or should I just leave them out?
For what you’re gaining in organic matter (and it’s not much when you see how much dry mass you really have when the weeds have dried out, you realise how much is actually water) it’s not worth the risk.
Thanks everyone for this great article and thread. I am new to Permaculture gardening this is of great help to me. I read through most of the comments and got a fair idea how to do it but have some specific questions:
1. I live in Napier, NZ and it is winter now with temperatures between 5 and 20 Degrees. I will do the compost in a very shelter warm place (north facing sun trap, sheltered from winds and under trees.) I will also try to insulate the heap with corrugated iron sheets and an old spa pool cover. Will that be sufficiently warm? Anyone did it successfully in similar conditions? If not warm enough will it then turn into an cold compost? And is there a way to restart the process in spring e.g. by adding high nitrate material?
2. I have a lot of old branches. They have been on a heap there for about two years and a very dry (top) or partly decomposed (middle and bottom). I have put some through the mulcher and the consistency of the mulch is crumbly, soft even powdery. I know that wood chips have a c:n of 400 to 1. With my old chips – would the carbon be higher or lower or stay the same?
3. I have some rich dark soil (forest floor) at the site and wonder if I should add some to make up the total volume as this is easier than carrying leaves and other material up the hill. I read earlier that old compost is high in Nitrate so I assume that this rich dark soil is on the same level than C:N as manure?
4. And lastly I have a number of thick half decomposed branches that won’t fit through the mulcher. But they still too hard/thick to be chopped up with a spade. Is it a good idea to throw them on as well?
Many thanks, Markus
1. Readers from the UK and surrounding countries have successfully hot composted using this method, it’s colder there than in New Zealand, if you just cover with a tarp it will be fine!
2. Wood is wood once it’s dried, your dry branches would have the same C:N ratio as sawdust and woodchips.
3. Compost is fairly rich in organic matter but it doesn’t contain the nutrient levels of a fertilizer, nowhere near enough nitrogen, and compost is actually a soil amendment, something that you add to soil to improve it. Making compost is basically making really rich soil (it’s how nature makes soil) so it makes no sense to be adding soil as a major ingredient in your compost, it’s like adding tomato paste as an ingredient when you’re trying to make tomato paste. If you have rich soil, add it straight to your garden, but for heaven’s sake don’t go digging it up from the floor or the forest if that’s where you are getting it from, that would really mess up a balanced ecosystem! Look through the list of ‘greens’ (materials high in nitrogen) in the article, I’m sure anyone can get at least a few of these.
4. Thick branches have no place in a compost pile, use them in a hugelkultur bed instead (I’ll write a DIY article on hugelkultur soon!)
Hope this helps 🙂
Hello and thank you for the great instructions! On June 4th in hot weather I started my first hot compost pile! It is doing quite well. I used lawn clippings, cedar sawdust, kitchen scraps, lots of coffee grounds, straw, and a little bit of composted horse manure. The pile is contained on two sides by pallets and measures about a meter by a meter by a meter tall. I have been fairly diligent about turning – every two or three days, and the temperatures have been consistently between 40 – 50 occasionally up to 60. All the kitchen scraps and almost all the grass has broken down. There is still straw pieces and sawdust visible. Now on June 19th when I turned the pile there is a lot of white – mostly in the material about a third of the way into the pile, as well as further to the outside. When I turned the pile, the center was a bit too hot – about 65. The moisture content is not anywhere near enough to squeeze a drop of water out of a handful, but moist nonetheless.
My question is, should I worry about the white? And should I make the pile more moist?
WHen I turned it, I added some more sawdust (not much – just a shovel full between layers) to try to lower the temp a bit.
And finally, when will I know it is done? Will it cool off on its own? Or should I spread it out to cool? Let it go crazy hot?
Thanks in advance for any advice, regards, PIlinka
That’s exactly what is expected to happen, as the article describes!
The compost should have been turned on days 4, 6, 8, 10, 12, 14, 16, 18, a total of eight times. This system turns the compost the minimum number of times to complete the compost in the shortest time.
If you skip days you’ll turn it less, so the materials on the cooler outside of the heap wont get the same amount of time inside the hot centre of the heap, while the material in the centre overheats because it spends 50% longer there, as indicated by the white material that forms.
Just keep on turning it until all the materials are completely broken down, and it will naturally cool down when the process of breaking down the materials is finished. The reason the compost pile gets hot is because material is being broken down. 🙂
Hi, Thanks for your great articles, Faster compost we have to maintain C:N ratio & we have to apply Thermophilic microbes which is the best way to make faster compost.
Please suggest which microbes make faster compost.
Actinomycetes
Fungi
Bacteria
Those microbes may grown in 55-65 degree Celsius, please suggest somebody which microbes best for composting in your practical experience.
Thanks & Regards….
Yes, to get your compost heap breaking down quickly you need to have the right C:N ratio, but the bacteria do not have to added, they occur naturally. You can inoculate the compost heap with beneficial microorganisms if you like by adding some already made compost into the new compost pile when you first construct it.
Absolutely compostic , thank you.
Thanks for the splendid explanation. We are going to try hot composting in South India over the next few days.
I did hot composting in Dublin, Ireland. (It’s quite cold and wet.)
I read that the hot composting bacteria are highly aerobic, and use Nitrogen.
Adding a certain proportion of materials like straw, stalks, etc, helps air circulation, providing these bacteria with the oxygen they require.
Some things I found good are;
I put the heap right into the heart of the garden, where I want to prepare the soil for a new crop. It clears weeds, improves soil structure, soil life, etc. Any liquids seeping out of the heap will be absorbed by the soil, building up soil nutrients.
I put it right on top of the weeds.
(I know people who try to hide the compost heap under a tree or shrub at the bottom of the garden. I consider this a very bad idea. It makes it harder to turn it. It fertilises the shrubs so they grow too vigorously, and wastes the compost. I am pleased with the appearance of a large heap in the middle of my vegetable garden.)
To increase aeration, I lay down a thin layer of light branches, twigs, etc underneath. I reuse this in subsequent heaps. I want to allow a certain amount of air circulation under the heap.
I deliberately inoculate new heaps with material from previous heaps. I mix shovelfuls of old stuff through the new heap.
A bit of NATURAL wood ash is good. (Not chip board, fibreboard, plywood, etc. These contain toxic chemicals, and possibly fungicides, etc.) I believe wood ash is a good source of Phosphorous. Maybe a bucket full or two, mixed through the heap. I also add a handful of chalk, (cos I have it). (Seaweed fertilizer is a great source of trace elements.)
I always add several liters of urine to new heaps, pouring it over the finished heap. It’s an excellent source of soluble Nitrogen, which the hot bacteria require. It gets the heap going fast. (It also contains Phosphorous.)
I then cover the heap with one or more layers of black plastic sheeting, and weigh it down with bricks at the edges. This insulates it, and allows the temperature to build up quickly. It reduces evaporation, and protects from rain.
(This works well in Ireland. You can of course remove the plastic if you are concerned the heap is too hot.)
There are different species of earthworms. Some of them specialize in compost heaps, manure piles, etc. This is a good type to encourage. I got some worms from a manure heap, and introduced them to a compost heap once it had cooled down. (They will not survive in a hot heap.)
I kept these alive, and introduced them to subsequent (finished, cooled down) heaps if necessary. If you keep old compost around as a mulch, the worms can probably survive in that.
The worms further process the compost, dig the soil for you, and encourage soil organisms, fungi, bacteria, etc.
If you keep moving these hot heaps around your garden for a few years, you will have great soil, rich, dark, with a great structure, very easy to dig.
It really works for controlling weeds. Cover the soil in between crops.
The composted stuff is a great mulch, spread a couple of inches deep over all the soil, in between the plants you want to keep in your garden. Any weeds that show through can be cut off at soil level with a hoe.
There is a type of hoe called a ‘draw hoe’, or ‘swan necked hoe’. This is good.
I want it so that the blade is flat on the ground when I stand upright with my back straight.
(It probably requires a bit of adjustment with a hammer to get the angle right.)
Sharpen the blade well. Use it with a motion somewhat similar to lightly sweeping a floor, pulling the hoe towards yourself, through the mulch layer, just above the soil, moving it in between your plants, etc. The idea is just to cut off the weeds, without disturbing the soil.
If you keep it up for several seasons, you should have little problem with weeds in most situations. You build up a loose layer of composted stuff that has passed through the hot process, and had the weed seeds killed.
I’ve been a long term, Poland based hot composter.
My question is if U happen to have access to any sceintific studies on the fungi-exuded enzyme role in fitosanitation of humanure-fed compost.
btw. IMHO it shalll be emphasized that TMEPERATURE is NOT the MAIN factor that ensures total compost fitosanitation as most ppl perceives that way.
thanks for the great job in popularization of the topic
I’m not aware of the finer points of phytosanitation of humanure, but Nature more than adequately handles the recycling of all animal manures and animals themselves through the complex ecosystem of organisms that comprise the soil-food web. It has been doing this since animals first walked the Earth. The soil ecology does not depend on temperature but biodiversity and high concentrations of living organisms. Healthy soil can break down and sequester nearly any substance – but this is more a topic of soil ecology rather than composting ecology!
As I frequently promote the “closed nutrient cycle” in composting I must face the interlocutors fecofobia attitude
I always reply with the words U used:” but Nature more than adequately handles the recycling of all animal manures and animals themselves through the complex ecosystem of organisms that comprise the soil-food web” but then the question “how” arrives and when I give the reply I can see I’m loosing interlocutor’s attention but there are a few with bio-chem knowledge who drill deeper and want to know what are factors that destroys pathogens then.
So far I’ve met only 1 person who asked me what are the enzyms and what is the reaction mechanism.
I could only say than during the enzymatic reaction of lignin and celulose decomposition the radicals oxygen are produced which are heavily biocidal.
but that’s all. I wish I had more profound knowledge in the field.
btw as to the core article : I think this sentence “This is because the bacteria responsible for the composting process require these two misses the words “and fungi”
Hello,
I have a lot of tree branches (1″ – 1.5″ diam) cut 2 to 5 years ago (according to the cut lot).
After fine shredding this “dead” wood, can I use it in compost as “wood chips”? If so, what would be the C: N ratio?
That would have exactly the same C:N ratio as regular wood chips.
Keep in mind that all the C:N ratios are approximations, and can have some variation.
NIce !
Anything else:
In the table of C:N, what do you mean with “cow manure, horse manure, poultry manure…” ? Pure animal dejections or a mix of these matters with straw ? These components are opposite and very different in C:N.
The figures refer to manure alone. Also, fresh manures have higher nitrogen levels than aged manures. These figures are all general guidelines, as materials will vary in their C:N ration from location to location and season to season.
Thanks for answer. But, not yet clear “for me”…
In my language, “manure” is indeed translate by “a mix of litter (often straw) and animal droppings”.
Based on your answer, I presume “manure” does mean “animal droppings” (f.e. from cow = dung). Am I right?
Yes, manure refers to just manure! 🙂
Hello and thanks in advance! I have quite a bit of compost which I made (hot) in the summer. Would it be better to:
a) use it now and spread around in the beds where I have pulled the plants?
b) leave it in a covered pile over the west coast winter?
c) put it bags and store that way?
My concern with spreading it now is that it might lose some of the nutrients over the wet winter here on Vancouver Island. But I wonder if it would be better to spread it to encourage the worms and good micro nutrients?
This is a great resource! Thanks again, regards, Pilinka
Definitely use it straight away, put it into the soil, don’t waste it by sprinkling it on top as mulch, the sun will dry it out and kill all the beneficial microbes.
If it’s summer, you should have mulch on your soil to protect the soil and save water, so place the compost under the mulch, or dig it into the soil, this way it will give the greatest benefit. If your compost is in the soil it won’t lose nutrients in winter or any other season as the nutrients and the organic matter of the compost will become incorporated into the soil.
Hi Angelo, I was very interested in your reply to Pilinka’s note. I have been hot composting for about 3 years now and very happy with my results, but I do diverge slightly from your advice. Because I am a no-dig gardener, I always apply about 60mm of freshly made compost as a surface dressing on my soil after harvesting a crop. To keep it protected from the sun and wind etc, I apply a mulch of cane straw on top. I leave it for a month to build worm and microbial activity in the soil before planting the next crop, and it works a treat.
Hi John, I’m also a very passionate no-dig gardener (see my article on No-Dig Gardening http://deepgreenpermaculture.com/diy-instructions/no-dig-gardening/) which is why I said “so place the compost under the mulch, or dig it into the soil, this way it will give the greatest benefit”. I couldn’t agree with you more, the best way to use compost is the same way Nature does, as part of a sheet composting system that builds soil under mulch, precisely what no-dig gardening replicates, which is what you’ve just described. I only include the option of digging in the compost because many people don’t use no-dig techniques, and laying compost of the soil surface unprotected negates most of the benefits.
Hi, in the picture you are moving the outer compost to a new place then placing the middle (hot) compost around this, would’nt this require a whole extra 1.5 mtrs of space to move it? As this is what the picture is showing.
Yes, that’s exactly what the picture is showing, you’ve understood it correctly.
The pile can take up one square metre on the ground and it will still work, in which case you will need two 1mx1m areas.
Thanks for the article, it taught me a lot. I had been trying to do hot composting in a tumbler and realized when I read your article this was not possible. I live in Louisiana and the summers are brutal with temps 90-95 degrees. I have attempted to build a hot compost pile. I layered oak leaves, shredded newspaper and cardboard, fresh grass clippings, horse manure, unfinished compost from my tumbler, dead leaves and flowers from my garden.
I am on about day 14 of my hot composting. I started with a pile about 3 foot high x 3 foot wide about 3 foot deep. By day 4 it was up to 145 degrees F (the highest it got). I have not been so good about turning every 2 days with work sometimes my schedule does not permit the time. I have been turning about every 4 days. On about day 6 I had an ant pile on the edge of my pile and I added more water and this seemed to take care of the problem. At day 12 I was at about 139 degrees F and 2 days later I am down to 120 degrees F. Yesterday when I checked the pile I had a number of mushrooms (around 12) growing out of the pile (around the sides not the center). I also have another ant pile on the edge. Am I doing something wrong that I have these mushrooms? IS it because I am not turning enough? I do see some breakdown in the center but still can make out some of the ingredients on the edge. I am moving those ingredients to the center. I know I need to turn more, but it is back breaking work and I am a woman in her mid 50s, but I am determined. Any additional advice you could give me would be appreciated.
Hi Robin, yes, that’s correct, you are not turning it often enough! The steps outline the minimum required times it will need to be turned to work properly. Any less and it won’t work as well. The critical reason for turning is to put the coarse material on the outside back inside the heap to keep feeding the composting microbes. Skipping a turning step causes the whole process to lose momentum and it cools down, as the material on the outside of the heap won’t be broken down.
You can speed things up and make it easier to turn the heap by breaking down your materials as much as possible before you begin.
Put any coarse materials through a mulcher first, or put them on the ground and mow over them with a lawnmower, or even chop them up with a spade.
The smaller the materials are broken up, the easier they are to turn because they don’t tangle up together and the faster they break down because the surface area is increased for compost microbes to act on.
Thank you Angelo for the prompt reply. I have broken down the materials as best as I could. I chopped the leaves with lawn mower, ran the paper through the shredder twice to give me small pieces, cut up plants from my garden into 1 inch pieces.
What about the mushrooms? Is that normal, should I be concerned? Also, any advice on what to do now. It seems to be cooling down but is not broken down all the way. I turned 2 days ago, it was at 120 degrees F and it has climbed back to 120. Doesn’t seem to get any higher now. Would you suggest I add more nitrogen (grass or horse manure) to try to get it to heat up again?
The mushrooms are there because there is lots of carbon-rich material on the outside of the heap that hasn’t been turned. Mushrooms break down carbon rich materials back into soil, that’s their role in nature.
Definitely add more nitrogen rich material to get the compost heap to heat up again!
Angelo,
Thanks for the advice, I added grass on Saturday (pile was down to 98 degrees F) and by Tuesday it was back up to 145 degrees F. I will turn again the next day or two.
I am thinking about my next pile. I work in an office and we throw lots of paper away. Could I use shredded copy paper with black ink in my compost pile or are there too many chemicals? Also, do you have any advice on making compost tea with the finished compost?
Great to hear it’s working!
Office paper is bad news all round, the paper is bleached which means the paper is laced with lots of very toxic chemicals, and the toner is fused to the paper with a type of plastic base, so it’s definitely not the type of thing you want to put anywhere near your garden. Send it off to be recycled, that’s the best way to use office paper!
My most recent hot pile consists of roughly 70% wheat straw and 30% cow manure, all obtained from a local farmer friend. As I piled it up barrel by barrel, each layer was soaked. Now, a couple days later, the pile is hot enough it’s hard to leave my hand in it for more than a few seconds. Will be done in a month or so.
Great site, thanks
Well, was at dump 2 days ago, some one dropped of load of old horse maure with straw, so I loaded some up and grabbed some green grass and back home, put in bin with cherry pits and yard waste, added water to make it damp, it’s about 4’x4’x3′ high, next morning was hot in centre, lifted up and steam came out.
With the horse manure being old dry and no smell, would it have lost some of its nitrogen and almost be more of a carbon?
Cherry pits (just purchased house, had a cherry tree in back yard, no one cleaned up under tree for years so they a few inches deep so all goes in compost) would the pit break down?
thanks
Hi Robert,
It appears that the horse manure has plenty of nitrogen in it if your compost heap is steaming hot.
The cherry pits are quite woody, they are like wood chips but less porous, they will break down eventually, the older ones will break down much faster.
It would be great if you can tell us how well those cherry pits break down!
Thnaks
thing are going nicely , , have a lot of bigger stuff in the compost pile small branches and stuff , looks really good and smell earthy , will take longer to break down some stuff , but that’s ok ,
was thinking of putting it in bottom of raised garden cover with paper and /or cardboard in a few days and let it finish there well I start one with smaller stuff , for a top dressing ‘
then the worms will have a place to live over the winter
cherry pits are breaking down some , but will no better when I have stuff all the same size
any thoughts on putting it in the bottom of garden and letting it do it’s thing under ground
thanks robert
The main benefit of compost is as a soil amendment, you use it to improve your soil to convert it into a rich, dark, living soil that plants love. By all means dig it into the soil, that’s where it will do the most benefit!
If you’re a no-dig gardener, or want to save time digging, just lay the compost as a layer on top of the soil and cover it with a thick layer of mulch (approximately 5-7cm or 2″-3″ thick), and the earthworms will dig it into the soil for you.
Hi Angelo,
My compost pile is rapidly cooling down and looking pretty good. I have a couple of questions. We are going into the winter months and I will use some of the fresh compost but not all. What is the best way to keep for next spring? It is located in a woody area under some trees in Louisiana. It doesn’t get really cold here, only a couple of nights below freezing for the whole winter. Do I cover it, do I need to put water on it to keep it moist? Should I move to my plant beds that I will use next spring that is now empty? IF so, so I need to cover it with mulch or straw?
Also, we have problem with red ants down here. I had problems when the pile was active. They would build their piles on the edge of the compost where it was cooler and dryer, outside edge would dry out, temps around 90 degrees F for the summer). I don’t want to use ant poison, I would pour lots of water on their piles but they would just move to another spot. I would get bitten pretty good when turning my pile. Tired of fighting with them. do you have any suggestions?
Just read your article on raised beds. Wish I would have read earlier, did a lot of digging in rocky soil. I really like the no dig method. I will try for my vegetable garden next spring. Thanks for all the great articles and advice. I have learned a lot from reading your articles on this web site.
Robin
It’s great to hear when people manage to successfully create a hot compost pile.
As to what to do with it, definitely put it in your plant beds and cover with mulch.
See my comments to Robert about putting it into the soil or in a no-dig garden.
The simple control for ants is hot (boiling water), then dig them into the compost when you turn it for extra nutrients.
Has anyone used sugar to speed up the heating process on a pile that has become inactive?
never have added sugar but inactive add more green
Hi Angelo
What a informative site you have. I have just completed building a timber framed and insulated composter 2.5 x 1.2 x 1.2m high with roof and really only to make the best use of the leaves I have here in the UK in the autumn. The remainder of the year would only be a small quantity of grass cuttings and usual weeds and of course the vegetable and fruit waste throughout the year. After reading a lot of the posts on your site I am still not sure if I can lets say take several weeks to fill the composter in summer months as I dont think I will have the volume of ingredients to fill it faster. Do you think that this would upset the compost process if it took say 6 to 8 weeks to fill the composter? Autumn is quite different as I can retrieve a cubic metre of acorns alone and a mammoth amount of leaves. Also do think that acorns are a good source of brown materials.?
Thanks
John
Hi. If the area is generally with the lowest temperature of 20 degree Celsius and the highest temperature is around 30 degree Celsius, will the compost burn when the surrounding temperature is high ? Shall we leave the compost under the sun or under a tent?
A hot compost pile will cope perfectly well with those temperatures. Organic matter tends to decompose faster and more efficiently in warmer climates, as seen in tropical climates!
Hi Angelo, can the compost be left under the sun or under a tent/shade? Thank you.
After you compost is made, the best thing to do is put it in the soil, as natural compost ids living, it is filled with beneficial microbes!
If you want to store it, just put a plastic sheet or tarpaulin over it to retain the moisture in it.
I have a slightly dirty pond which I use for all my water needs and lots of comfrey which I have in abundance seems to work a treat
Hi, I need your help. I am enthusiast new gardener and to save bucks I tried your idea and gather this components:
1. Municipial Solid waste (basic Kitchen Waste)
2. Cattle Manure
3. Wheat straw.
4. silt (irrigation water)
How can get good ration ? Advanse thanks for your attention.
Use the formula I explain in the article:
If ratios seem too complicated or confusing, you can work with volumes of ingredients instead to simplify things, aim to use 1/3 greens (nitrogen containing) materials with 2/3 browns (dry carbon materials). In other words, add one bucket of nitrogen-rich material to every two buckets of dry carbon-containing material.
Kitchen waste, cattle manure = greens (nitrogen containing) material
Wheat straw = browns (dry carbon materials)
silt from irrigation water is just silt, probably composed of sandy finely broken up rocks, not sure why you would put that in unless it contained organic matter.
Hope this helps!
Hi Angelo,
Can I put citrus plants (peelings or over ripe oranges, manderines, etc.) in compost? I had read somewhere that it is not good to put citrus plants in compost piles. Looking for advice from the expert. That’s you.
Robin
You can use small amounts of citrus peel or fruit in your compost, they will break down in a hot composting system, but in a regular slow cold compost they will take a very long time to break down, so go easy with citrus when composting! Cut them up which down faster.
When I have large amounts of citrus peel or fruit that I want to add to my slow cold compost I put them in my Bokashi bin first, then they can go into the compost and break down very quickly.
Very nice article. Thank you very much
I make compost mainly using fruit wastes.
I added row materials for a 1000 kg pile as below;
All materials Crushed to 4 mm particles
1.> Pineapple, Banana, Water Melon etc 500 Kg
2.> King Coconut Husk Dust – 200 Kg
3.> Green Manure – Gliricidia – 150 Kg
4.> Cow Manuare – apply for all layers as a liquid – 100 kg
5.> Smoked Rice Husks – Charcoal – 50 Kg
6.> Fish Hydrolysate Fertilizer
Cover the heap using black polythene. Temperature is 70-80 C.
But in a 30 Days time it had done only 40% decomposition. Does my pile Ratio is wrong? How can I decompose this in a 30-45 days?
Should I add Microbes Inoculate? How I make that?
Please help me.
You have a 1000kg heap that is not beiung turned!
The problem is that it is getting too hot, and there is not enough oxygen getting into the pile.
Try the method I describe in the article above, it’s just three easy steps:
1.Build compost heap
2.4days no turning
3.Then turn every 2nd day for 14 days
With that quantity of compost you will need to use a front-end loader to turn it, using earth-moving machinery it should be very quick.
The problem is that your compost is getting too hot, and is running out of oxygen because you are not turning it.
Try the 18 day Berkley method, the procedure is quite straightforward, it’s just three steps:
1.Build compost heap
2.4days no turning
3.Then turn every 2nd day for 14 days
Use a front-end loader to turn it, it is too much to turn by hand.
Hi, i need your help. i have a task about making efb compost with woodchip and chicken manure. but the problem is i have only 600 g of efb. i need to make efb compost into 3 comparment at different ratio efb. the only i want to ask it is the chicken manure weight that need use is high in short time. i just want to make small compost only..help me
hello..im really need your help. i need to analyse 600g efb only with chicken manure,woodchip.
and i need to make 3 compartment with different efb ratio to test.
so i make ratio 1oo g efb:100g:100 chicken manure
200:1oo:100g 300g:100g:100. but i see the compost is dry. it is i need increase every chicken manure weight.
please help me
Can human poop be used in composting, because I have to take the browns to the super bowl:)
Please refer to the previous comments March 26 2012 and later regarding ‘humanure’, I think we’ve covered the subject already!
Hey this is the best composting site I’ve seen.
Do u have any videos on YouTube or something like that?
I’m dyslexic so reading is hard work, videos make it easy 4 me
Thanks 4 such a good site
Hi Rob, thanks for your comments, unfortunately we don’t have any composting videos yet, thanks for the idea, hopefully we can do one in the future!
Thank you so much Angelo! This is AWESOME! I have failed at my composting efforts previously and after watching your geoff lawnton video Im bursting to get started on my own urban edible garden. How inspiring!! Appreciate your efforts in sharing your knowledge 🙂 Peace
Superb Article, I was searching for this from weeks, and finally got it.
I am going to start farming from next April and for that I need to create Compost. Mostly I am going to use Cow Manure for this as it is easily available at my place. would be using little amount of vegetable/green waste and little bit brown material.
I need to create compost in large Volume around 20 Ton. will follow all the steps and instructions mentioned in the article.
I have below question please try to clarify/guide asap.
1) is above mentioned material enough for compost or I need to mix other thing?
2) can I increase size of heap as I need to create in large volume?
3) do i need to apply water when I am turning the heap?
4) do I really need shed for the heap? Can I do it in ground and cover it with plastic?
Again highly appreciate your provided information in article.
Waiting for your valuable response
Thanks in Advance
Regards
Dinesh
Thanks for your comments, please follow the instructions carefully if you want to make compost in 18 days.
I have written the following in the article in RED so people will not miss it:
NOTE: If ratios seem too complicated or confusing, you can work with volumes of ingredients instead to simplify things, aim to use 1/3 greens (nitrogen containing) materials with 2/3 browns (dry carbon materials). In other words, add one bucket of nitrogen-rich material to every two buckets of dry carbon-containing material.
You can create a heap as big as you like as long as you have the equipment to turn it.
Yes, you need to maintain the right moisture levels, if the compost heap fries out, it stops breaking down!
You shouldn’t need to cover your compost heap at all, it will be big enough to stay hot and you are in a warm climate (assuming India or that region by your name).
Hope this helps
Thanks a Lot.
Hello,
I am very interested to find out about in-vessel composting using the shipping container design concept with air-ration included. I am in the Middle East so the temperatures will be high during April-November. We think this method could be faster, good to retain moisture during curing and breakdown process, and also portable as we have 3 sites.
Can you please offer any advice to guide me as this is very new to me.
Thanks
Thanks for your email, designing closed-vessel commercial-scale hot-composting industrial equipment is engineering design work which unfortunately is beyond my field of expertise as a horticulturist!
Hi there! I have used your method successfully and love it! A question I have is whether or not you think that citrus peels are okay to compost? We have been using quite a few lemons and oranges per day, which add up in the bin. All the kitchen scraps go in the bin which then gets used for hot compost when there’s a goodly amount. I have read conflicting opinions on citrus peels. What do you think?
Using a lot of citrus peel in a regular slow compost is a problem because the citrus oils kill bacteria and slow down the compost so it just sits there for a very long time without breaking down. In a hot compost system the heat will break down the citrus peel very quickly so it won’t be a problem.
Will adding amendments like kelp and alfalfa be beneficial to the pile in terms of nutrition? I understand that these amendments may get the pile started but if one can use other greens like comfrey or grass, then adding amendments might not be an efficient use of organic nutrients. Would adding these amendments AFTER the pile is complete a better idea?
Also, I was able to get a pile to reach 145ish F while only containing 14 gallons of material within a plastic bin at a C:N ratio of 35:1. Not sure how long the pile will remain at this temperature — if it only heats up in this 140-155 F range for fewer than 18 days, should I consider my pile not completely composted?
The greater the variety of ingredients, the better your compost.
Kelp, like other seaweeds, is very rich in a wide range of minerals, and it also contains growth stimulant substances (cytokinins and other cytokinins-like compounds) which are natural plant growth biostimulants. I would add the kelp to the garden afterwards as the heat of the hot compost might break down the growth stimulant substances in the seaweed.
How do you tell if your pile is completely composted? You shouldn’t be able to recognise any of the ingredients in your compost, as I mention in the steps at DAY 18 – Just warm, dark brown, smells good.
You don’t have enough compost for a true hot compost heap, I state in the instructions that the heap should be 1.5m (5′) high. Even at 1m (3′) high your heap at 1 cubic metre ( or 3′ x 3′ x 3′) will gave a volume of 1000 litres or approximately 264 gallons! The ideal temperature is 55-65 degrees Celsius (131-149 degree Fahrenheit). Your compost at 140-155 F is within the range, a bit too hot, but any small compost heap with enough nitrogen will quickly heat up, and cool down just as fast, this isn’t a true hot compost, it’s just a cold compost that starts off very hot. The whole point of hot composting is a constant high temperature for a long duration which literally ‘cooks’ everything to break down the ingredients completely, and kill off any pathogens and weed seeds.
Hope this helps
Thank you for the in-depth response. Since there is really no way of knowing whether cytokinins and auxins from alfalfa and kelp survive the hot composting phase (vs mesophilic phase), I’ll refrain from adding amendments in the future.
With such a small pile, my goal is to continuously add a nitrogen source every time I need to turn it (when temperature approaches the lower range) and slowly bring the C:N from 35:1 to 30:1 over the span of a month or so. So far, the pile reached 145 F for about 24 hours and cooled down to 120 F thereafter — after mixing more coffee and adding water, it’s back to 145 F within 8 hours.
Would you consider this successful composting if the end result “looks” the same? My concern would revolve around other underlying issues ie losing nitrogen content or not developing a diverse enough microbe population within the pile, etc.
I would say it would be better than most cold compost methods but not as good as a proper hot compost. You will lose a lot more nitrogen than in a hot compost pile and you may not get rid of all pathogens or weed seeds. Treat it as a faster cold compost, because cold composting can also get hot for short periods when you add enough nitrogen containing materials in the mix.
What happens to the ink in paper when composted? Is it ok to use in a vegetable garden?
Most newspapers use vegetable based inks so they’re safe. Never use office paper (full of toxic chlorine compounds from bleaching) or glossy colour magazines because the ink is a synthetic (acrylic paint). Many things will break down in a properly made hot compost heap but it is best to avoid glossy colour magazines or office photocopier/printer paper, but newspapers are fine.
I have done something similar in April/May last year, although it was an accident! But I havent been able to recreate the right conditions. So, thanks for the information! I want to start my compost heap tomorrow.
However, it is rather cold where I live. It is about -2 C (27 F) during the nights and +5 C (41 F) during the days. Also, there is a lot of rain coming from day 3-9 of my compost heap and my garden is in between 2 streams so the soil can get almost swampy during the day while frozen during the night. Do you think I can still perform hot composting? I thought it may be good to lengthen the duration to turning every 3rd day considering the cold atmosphere. And of course cover it with plastic.
With regard to the pile: I have a lot of kitchen scraps, coffee grounds, fish, some wood chips, a lot of leftover sturdy plant matter and leaves. So I think I have the ratio covered.
Would really appreciate any advice you may have!
Sorry if I have posted this twice, but posting doesn’t seem to work…
We have readers who have built hot compost piles in the UK, it gets cold there! I would cover the heap to keep the heat in, a plastic tarpaulin sheet works fine, and if the pile is sitting on wet ground covered with water, choose an undercover location where it is drier preferably, or you make platforms out of recycled wooden pallets to keep the compost heap off the ground.
Posting comments here ALWAYS works! The first time any reader posts a comment it is held for moderation which I must approve, only after that your comments will appear immediately 🙂
Angelo, thanks for your reply. Previous comments of people in the UK and surroundings were mostly posted in Summer, so I thought that would be rather different (about 20C difference actually). Anyway, I tried it. Doesn’t seem to work as fast as you said it should, but it is coming along now 🙂 I’d say the heap is now – 2 weeks after I started – at 1/3 of a completely composted pile. Maybe I’ll put some more fish in the middle next time I turn it to speed it up a bit.
I want to start a new heap soon as I am making some new vegetable beds that I feel need a little elevation due to the all the swamp-like features of my garden… Problem is, I’m running low on materials and my country is really keen on cleaning every bit of leave, branch etc. come Fall, so no chance of getting extra materials at the beginning of Spring. So I was thinking about Hugelkultur beds later in the year. I should dig them in a little, because I don’t have much spare soil (so dig up soil come on top of the wood). But this means I am tilting the soil. Would this do more harm than good? Also, my soil is VERY compacted and is mostly loamy soil with some clay.
Appreciate your advice!
Hello again! I have a question that is a bit off topic – What are your thoughts on using pine needles as mulch? Instinctively, I thought that it would not be good, as nothing much grows under pine trees, but my Mom who lives in Italy and has access to lots of pine needles thinks that they make good mulch. Have you any experience with using pine needles?
Thanks in advance, regards, Pilinka
Pine needles make a great mulch that breaks down VERY SLOWLY and makes the soil ACIDIC – perfect for growing blueberries and other acidic soil loving plants. Terrible for plants that need alkaline soils though…
I have a little wood of 1000 “Picea Abies”; thus, not reel “Abies” (Pine) who are much better.
But I use the needles of my Picea’s a lot since more then 20 years (they are there)!
It’s a very very good mulch (I only use this mulch for the potatoes and they’re very big) ! Best is to put a minimum height of 4″ (10 cm) as “mulch” and 8″?10″ (20 ? 25 cm) to clean the soil from other plants.
Be sure there is no problem to put a height of 8″ on potatoes (who may only be disposed just “on the soil”, under the mulch = without planting). This mulch has to be wetted on placing; not more after behaf if hot wether for a long period. That’s the reason 8″ to 10″ are necessary.
I also use a parcel of those needles in my compost pile. With composting, there is not any problem with the acidity of the needles. I work so more then 20 years and put my compost anywhere : under all the fruit trees and in my vegetables garden.
After this long period, I think I have a honnest experience with (Pine) Picea’s needles.
Compost that is produced with the hot compost method is usually very slightly alkaline, whereas slow cold compost is usually very slightly acidic.
So pleased to see that this article, with comments, is still current. I am fascinated to learn that hot composting can produce humus in less than 3 weeks. My present predicament is that, as the manager of a large DIY yard, I need to turn 45 stables worth of horse manure into black cold compost on a continuous basis, and the quicker the desired product is achieved, the better. If I tell you my plan, maybe you can tell me the pitfalls or misconceptions in it.
Firstly the stable manure goes up an elevator in to an 18 cubic meter agricultural feeder mixer wagon where it is mixed for about 15 minutes every day until full: about a week’s supply. It is then disgorged into a large concrete composting bin, dims 1.8m x 3m x 6.7m ( with concrete base, covered by a metal sheet roof)
The second week’s supply is then mixed with it {using a muck grab or 2 metre bucket on a JCB telehandler and put back into the bin. This mix is then transferred into a similar sized second bin, and moved from one to the other twice a week until ready.
Pure horse manure is the major constituent of the mix. The rest is made up of straw & straw pellets, hay sweepings and hemp.
Will this work? Thanks for your article. I look forward to your reply – John
This method will produce compost, albeit fairly slowly, as you’re turning the compost only once a week.
Many commercial operations use very long high rows of compost laid out on the ground which are turned very frequently with a windrow compost turner or a front-end loader for fast hot composting.
I tried hot composting. I filled the plastic container (drilled with holes) to 3/4th with food scraps and dry leaves. I wet it with water too. Then I out a lid to it and kept it under the hot sun(really warm here 30 C). The next day when I opened to check it I saw the top leaves had become dry and inside it was really warm inbetween. It was then (or the next day) that I noticed *ugh white worms and red eggs of worms. There were some 5- 6. I immediately spread out the pile under the hot sun and the worms went away. I thought it was because of too much moisture. So I decided to dry out the pile on a plastic sheet for two days. Again it is back in the container now. I don’t close the lid now. The pile is all dry and no worms. I have watered it again now. I turn my pile everyday coz it becomes very dry otherwise. I water it everyday too. The container was filled to 3/4th of its capacity and now it has reduced to just half. The whole heap has become dark brown in colour and has earthy smell to it. Of course, nothing has broken down yet. it has been 13 days or so since I started this compost. please let me know if I am doing something wrong. Why did I get worms? should i water it often? I am a bit confused. thanks a lot for your guidance.
Hi Cindy, I’m confused too, I don’t think that’s quite hot composting, it’s not what I’ve described in the article!
Worms break down decomposing organic matter when it is cool enough for them to feed on, that’s what they exist to do, that’s their job in nature 🙂
also is it ok not to turn how compost for 4 days in this warm weather? i am afraid it will catch flame. it is 30 C here and soon will move onto 40 C. thanks
It’s important to follow the procedure for turning the compost or you wont get hot compost in 18 days, you may not even get to make hot compost at all if you don’t follow the procedure and let the pile cool down before it is ready. No need for concern, a hot compost pile will NOT spontaneously combust and catch fire! 🙂
thanks a lot for answering my queries. really appreciate it. 🙂 from what I understood from your explanation, worms will exist in compost. I think I will skip composting then. *lol guess my so called hot compost has become cold. can’t imagine my terrace being invaded by worms. *a big ugh
Very thought provoking. We are going to do this. It’s still very cold here in the UK with daytime temp average of 10 C degrees and 4 C night can still frost.
I see a previous poster recommended that if threading through (horizontally and vertically?) pipes with air holes….then you may not need to turn.
Did you try this out. I’m wondering if we still need to turn or not. Family member has one arm….but if we have to turn we will pitch in.
We have a regular supply of hops from a brewery..good?…or is manure ( we can get both fresh and well rotted horse manure)
The use of slotted pipe was to wrap inside a small plastic compost bin to speed up cold composting that doesn’t get turned. Any turned compost will be faster than unturned compost, and hot faster than cold.
If you cover the hoy compost with a tarp, it will retain more heat and won’t cool down as much in winter.
Manure would be a richer nitrogen source than hops, but it would be better to add both in the hot compost heap – more ingredients is better than less as it will contain a wider variety of nutrients that way.
Ah, I’m with you. I’ll mix both as got good supply of both…negotiating with coffee shop to get spent grounds too.
Many thanks for an extremely informative site
I see you may have some kind of retaining posts?/ wood either side of your pile?
I have access to pallets that would help maintain height/ keep together to help cover pile in particularly wet Welsh weather?
I can strap thesetogether so easy removal and access to outside of pile for turning “outside-in”.
Would this be ok or is it meant to all be loose ?
Another question, would you consider spent hops from brewery to be green or brown layer. I’ve read that hop much is slow to disintegrate but wasn’t certain if this meant it’s ” brown”
Another question ( I do hope this isn’t being too demanding on your time/ experience).
I grow tomatoes and cucumbers under glass in pots. I usually chuck this onto outside beds but did wonder if putting some of this in your system is a way of heat sterilising. It would however potentially mess up the balance of your system?
Hello again, i decided to go ahead with your instructions on hot pile and created this compost pile 2 days ago in a 3 feet tall plastic container drilled with holes. The thing is, i inserted this metal rod into the middle of the pile and tested it. very cold and damp from day 1. even on day 2 it is cold. what to do? what went wrong? i didn’t close the container though. thanks
Hi Cindy, you’re using a container for hot composting? How do you turn the sides to create the centre of the new pile?
well, yes, i am using a plastic container. i don’t know much about composting. i simply tilt the whole container and mix everything with a trident . i don’t think it should affect the plastic coz things are just lil bit warm. not much but lil. that’s how it was today.
Hot composting needs quite a large volume of material to get the heat up, more than most containers will hold. In hot composting you dig the outside layers first to create the centre of the new pile when you turn it. That way, the coolest (outer) parts of the compost heap become the hottest (inner) parts of the heap. The garden implement you’re using is just called a garden fork 🙂
I’ll have to write an article on fast cold composting in containers soon, I feel there’s a need for it.
*lol pls do write that article on fast cold composting. it is very funny that i tried hot composting and it became cold. i can’t get hold of that much of materials. anyway, thanks for everything. 🙂 will keep a chk on your site for that article. 🙂
I am working on communal garden where we have 6-8 week hot compost going. we have been advised that we cannot use the compost that comes out straight away and that it is best to grow potatoes in it before putting it on other crops. or at the very minimum until it has cooled down. Please can you advise on your experience of this?
6-8 week hot compost? It should be cool and ready to use by day 18. How is it staying hot for two months?
Once it has broken down it is ready for the garden.
Hi Angelo, just wondering, is it a good idea to compress the pile slightly? My current pile is about two meters wide at the base, and at least a meter and a half tall. Every now and then when I piled/turned it, I stepped up onto the pile to even out the compression so the the edges are as compacted as the center. What do you think? I know it’s an aerobic compost, but thought that with the straw and rough browns there would be enough oxygen to feed the process.
My gardener friend tut tutted me when I posted a picture of me standing on my pile 😉 🙂
I have to agree with your friend, compost needs oxygen, those air spaces are critical, if you compact it you will slow down or stop the natural aerobic composting process!
Both soil and compost should never be stepped on or compacted. Garden beds are for plants and soil organisms, garden paths are for people, and compost piles are for microorganisms and earthworms. 🙂
Oops! Duly chastised! No more stepping on the pile! Turned again today, temp is coming up to 120 with each turn. I am so excited every time it reaches a good temperaure! My friends think I’m a bit crazy about compost – and they’re right, I am! Thanks for all your help. <3
Sounds great, you should have really nice compost in no time! Yes, we’re all crazy about compost (and Nature in general) here, so you’re in good company 🙂
By the way, occasionally my pile doesn’t heat up to active temperature after a couple of turns. Do you think it is better to add more green at that point, or to let it sit an extra day or two? The first three turns have been good, but now the pile has cooled a bit. Also, should I re-wet the pile if it starts drying out a bit?
Yes, if the pile starts cooling, add more nitrogen-rich material, manure is good. If it starts drying, add a little water. I’m guessing that if its both drying and cooling, the problem is not enough greens, which contain nitrogen and water.
Great way of composting.Through composting one can easily use their waste material for a good cause and save environment from pollution.You did a great work by sharing your views with us.Thanks for your wonderful work.
hello , thank you for all the info and guidance. we are using round steel wire mesh rings of I mtr height X 1.2 mtr dia for composting kitchen waste + dry leaves in layers. we use saw dust to raise the C : N ration n reduce moisture. Would like to use Cocopeat i/o saw dust ,. we are into dry 40 degrees C ( new delhi, INDIA ) . Can u comment on the advantages/ disadvantages ????
Coco peat (coconut coir) has a carbon-nitrogen (C/N) ratio of 104:1 75:1 to 186:1 which is much lower than Sawdust 325:1, on other words, it contains more nitrogen and less carbon than sawdust, so you’ll need to use more coco peat than sawdust to get the same carbon levels.
Thank you angelo, That makes sense , the reason to consider Coco peat ( we have a cheap source but it has some vermiculite in it which was once used for saplings and discarded ) its aeration qualities as sawdust tends to compact ( to reduce having to turn the pile ) water absorption n release qualities, also since here we add cocopeat to our potting mix later in any case .
Henry Gordon,
Great, speedy composting, waiting for over 6 months is really time consuming. After following your procedures, I m getting healthy compost for my plants every month. I have tried heaping up my compost bin with piles of newspapers which gives good result.
Up here in Vancouver, BC, we have raccoons, skunks and moles in our yards. How can we keep them out of the compost and/or discourage even more of them in our yard? They defecate and scavenge our gardens already so compost might make it worse.
I reckon you have nothing to worry about. At the temperatures a hot compost pile reaches, no critter is going to start digging into it while it’s in production. In fact, some people put dead critters (roadkill that they’ve collected off the street) into their hot compost as an extra nitrogen source and only clean bones are left when it’s done.
Also, when the compost pile has cooled down after 18 days, all that will be left is a rich, dark moist compost, there’s nothing left that critters can eat.
Since its my first attempt at composting of any kind, i thought to build the hot composter with close boarded pallets on all sides. Do you think i need 1/2 inch metal mesh (20 ga.) on the bottom foot surrounding the composter to keep out any mice and small rodents since it will take several days for the hot composter to get hot enough to deter wildlife?
Hello Angelo,
I have access to a barber shop and have already asked them for the hair cuttings. I can’t get my hands on manure so I plan to replace it with hair, but before I start gathering I would just like to ask a few questions.
1.Do you have any info about the n:c ratio of hair? I noticed you don’t have it in the chart above.
2.Can I use hair treated with chemicals(e.g. hair color, straightening, etc..), or I’m better off using untreated hair?
Thanks.
Hair is very high in nitrogen, it even has a much lower C:N ratio than manure!
Now the bad part – hair accumulates heavy metals such as Cadmium, Lead and Mercury at higher levels than the body. Scientists are using this phenomenon as a means to assess exposure to heavy metals through hair analysis. One such reference is:
R. Pereira, R. Ribeir, F. Goncalves, Scalp hair analysis as a tool in assessing human exposure to heavy metal, Science of the Totala Environment, 327, 81-92, 2004
If hair has been chemically treated, that’s even worse. Aniline based hair dyes are toxic, as are many hair dyes that contain para-phenylenediamine. Some hair dyes even contain lead in the form of lead acetate!
Just for my amusement (as a qualified toxicologist), I looked up what poisonous substances are in hair dye and was shocked. From the University of Maryland Medical Centre website, under ‘Hair dye poisoning’ in reference to ingesting the stuff, there is the following list:
Poisonous Ingredient
Permanent dyes: Naphthylamine, Other aromatic amino compounds, Phenylene diamines, Toluene diamines
Temporary dyes: Arsenic, Bismuth, Denatured alcohol, Lead, Mercury, Pyrogallol, Silver
It’s actually worse than I thought with hair dyes. Best not to use hair in my opinion.
is it possible to hot compost with sod? if so, how should we layer and prepare it?
Sod (turf) is just grass with roots and the soil beneath it that the roots are still holding onto.
Treat it as a high nitrogen material similar to lawn clippings when hot composting it.
do i need to break the sod up before composting as it is in big strips rolled up?
You’ll have to break it up anyway when you turn the compost, it will be easier to turn and will compost faster if you break it up first. One of the rules of composting is to break up your materials as much as possible to increase the surface area available for the composting bacteria to do their work.
Thanks for the feedback Angelo and great site by the way. We followed your advice and consider all the points you mentioned when making our compost pile. We made alternating layers of chopped up sod and water soaked shredded newspaper to build a pile about 2-3 feet high soaking wet. On top of each sod layer, we add urine to ‘activate’ it and then covered it with a black tarp overnight to try and contain whatever heat might be produced.
Unfortunately, no heat at all was generated in the compost pile. The overnight temperature was 7C (45 F) and the high is about 13C. Where did we fail? Not enough ‘green’ due to the sod composition? Too wet? Still need more material to build a large enough mass? How can we ‘fire it up’?
Is it possible to make a make a hot hugelkultur bed?
Our small rented lot drops off in the back about 5-6 ft. I’m trying to figure out how to fill it up without paying for dump truck loads of dirt, especially since we are just renting the lot! We are at the end of the trailer park and surrounded by forest trees, a field of grass/straw? that sometimes gets mowed and baled into huge round bales and sometimes gets ignored. One of the bales got left behind a few years ago because it rolled into the edge of the tree line. Thinking about piling up dead branches, trees, the old bale of dried grass/straw?, leaves, pine needles, crumpled up newspaper, possibly some manure. Figured the cut up branches and logs would go on the bottom, then the leaves and newspaper, then the straw/dried grass, and hopefully some manure, then leaves and pine needles. Would that be the correct order?
We plan on taking out a row of tall hedges that grow red berries on them to help “open” up the narrow lot so we have room to walk past the deck. Plan on adding them to the compost pile/hugelkultur bed. I’m guessing since they are very woody with short pine needle looking green tips growing along the branches that this would be a nitrogen source since it is “live”.
Also the lawn is basically non-existence. It’s compacted clay soil, grass full of thistle, dandelion, lotus tree sprigs, multiple bare spots. Thinking about just digging up the first 2-6 inches of dirt and getting some topsoil from somewhere and then planting grass seed. Would that be unreasonable? Good idea? What methods, tools would you use to accomplish the task?
I have followed all your comments to build a hot compost pile: chopped the sod up for layering with water-soaked shredded newsprint to a height of about 3 feet in a 3 foot circled surrounded by mesh fence, covered with air gap under black tarp. Added urine to the sod layers as an ‘activator’ while night air temp falls to 7C from 13C in the day.
Still no heat – what have I done wrong? Too wet? Not enough green since sod is more soil by weight?
I would say definitely not enough nitrogen and too much inert material (soil). The soil attached to the grass roots is not a compostable material and basically doesn’t do anything other than reduce the amount of usable materials for the composting process. What total percentage of the compost pile is just soil? It should be minimal!
Thank for getting back to me. To remedy this, should I abandon my current stack and start again or keep adding greens to it since the sod is about half soil and half greens&roots? If u continue, what do you suggest to fire up the stack?
Use the materials of that stack as one of the materials in new stacks that are made using the correct proportions of ingredients and you’ll be fine.
Hi Angelo,
Added grass clippings from a landscaper to get the pile hot. but now it is constantly gettign too hot, running no less than 90C overnight. The pile has shrunken a bit since it got hot. Should l buy from Lowes “North American Pellets 40-lb Wood Pellets” for more carbon to cool it down? Would you know if it is safe to use in hot composting for vegetable gardens? Thanks for your reply.
I would just use newspaper, cardboard, egg cartons, sawdust, dry fallen leaves and other such sources of free high carbon material.
Experience feedback …
Hello Angelo,
Since June 2015 I made 3 piles (+/- 1m each), applying (as best as I could) your instructions.
For each heap, I got a “hot” process immediately. Great, it works.
After 4 days and first reversal, I got heat again in the pile made in “summer”.
The pile made in the fall gave me a warm reaction too, but only for a very very small part of the pile. The pile made begin April gave the same results as that of the fall.
But for all the heap, the third process (after the second reversal) and others gave only a cold compost and wood particles are not decomposed.
The shorter time required to obtain a compost “usable” (after filtration) was approximately 1,5 months (for the heap of summer). The pile began in fall took more than 3 months and lots of particles (thin branches) are not yet decomposed.
The pile began in early April went dark, but still quite cold and all brown materials were not broken. I restarted this pile with grass at the fourth reversal and have then waited 4 days before following reversing. This has revived the heat 1 time, and is then completely returned cold again. It’s at its end now and it seams totally like the other piles at the end of the 18 days.
Yet I have used the proportion 1 green fork + 2 (same volume) brown forks.
The leaves give the biggest and quicklest heat.
The thin branches of trees do never disappear, but become completely black.
The grass and other greenery disappear (transform) very quickly (too?)
The heaps have a correct moisture and dry only on the outer surface (on +/- 1′ deep).
The only thing that I noticed is that I did not have high weather temperatures for the last 2 piles (between -5 C and 18 C), but well for the first.
In any case, I find that :
– all materials and the whole volume is not “heat-treated”; I would say… 1/3 at most;
– the final compost obtained is… I would call “young semi-mature”.
– never a worm in my cold piles.
Thank you for your opinions.
Thanks for sharing your feedback. Materials we class as ‘greens’ – the high nitrogen materials, they vary considerable in their nitrogen content, which is why I encourage gardeners to use a mix of materials. If the compost cooled down early, the nitrogen content wasn’t high enough. Using manures in hot compost piles gets them really nice and hot.
Thanks for your reaction.
Well, as “green”, I use :
– kitchen waste,
– grass (a lot)
– horse manure (even as grass)
– dead raw fish (from a koi seller). Theses fishes don’t brake out rapidly and… that smels hard when opening the heap !)
You have a good mix of nitrogen-rich ingredients there, so that looks good. That would suggest that you probably need to fine tune the proportions of high nitrogen to high carbon ingredients. Perhaps you might need to use more of the high nitrogen ingredients into your compost heap when you first build it – sounds like it starts well, then all the nitrogen gets used yup early causing the heap to cool down.
OK, I understand what you mean.
I wil try with more grass and horse manure for the next pile.
Thanks for your comments.
Hi Angelo, we dont have a source of high carbon such as dried leaves or sawdust. My wife feels that newspaper needs to be micro-shredded and wet to have a chance of decomposing. Do you concur as we would have to invest in a shredder for this?
Don’t shred the newspaper, that’s not necessary. Just tear it into pieces by hand.
An even better method is to take whole single newspaper sheets (without tearing them) and crumple them into balls and throw these into your compost. Each sheet makes one ball. They create great air spaces which aerate the compost nicely, allowing oxygen into the heap which makes it break down faster.
Good day sir, I am a college student from Philippines and while searching for some related studies about our research paper I saw this article which give me so much knowledge in composting. I, with my group mates, is trying to create an automated organic fertilizer processor. Sir, as what we saw from this article your steps are really easy to understand and is very systematic, is it okay sir if we will use your steps in our automated organic fertilizer processor? We will be very happy to use this method and of course acknowledge you in our study. Thank you and more power. 🙂
Anyway sir, may I know your name? thanks.
You’re welcome to use this method, and you can find my details here – About the Author
Nice article.Thanks for sharing great ideas with us.
will cardboard slow heap down
No, it is a common ingredient used to add carbon to the compost heap, so if there is enough nitrogen-rich material to balance it, it will be fine. If you add too much carbon material of any kind and not enough nitrogenous material, the compost heap will naturally slow down of course.
You’re welcome!
Hi, I’m planning on starting my first compost in a trash bin (20 gallons). Is this a bad idea? I was just going to roll it around as my way of “mixing” it. How thin should I layer the browns/greens? Also, do you suggest putting twigs as my first layer at the bottom? Should I add some soil between the layers and if so, how much?
That would be just like using a regular tumble bin that is used for cold composting. Yes it will work but it will take a while to compost the materials, probably the fastest would be six weeks if done during the warmer seasons. Don’t put twigs at the bottom, there is no point as your rolling the bin to mix things, just break up all the materials as fine as possible, and use thin layers of each material to make it as easy as possible to mix everything up together.
Hi, I started composting 1 month ago. I own a urban chicken coop and I am using wood chips as bedding material. For my compost pile, I start using, as we produce them, waste from chicken coop, shredded newspaper and grass clipping. I also have some kitchen waste, but my chickens are eating a big part of it. I guess I didn’t understand well the functionning of the ratio at the beggining and I was using more wood chips than grass or the same amount. When I turned my pile earlier today, the grass was “gone” but we can still see all the wood chips and the newspaper. What I did is that I rebuil a pile by layering this compost with fresh grass clippings to add nitrogen. Was it the good way to go? Sorry for my english 🙂
If the wood is left but the grass is gone, that would indicate that you don’t have enough nitrogen-rich materials in your compost. The grass alone may not be enough, you might need to add manure.
Thank you Angelo. I have chicken manure fertiliser I bought before I got my chickens. I will mix that into the pile. I really like this post 🙂
I was just wondering, can I use animal blood (cow and/or goat fresh blood) as activator or booster? There is a slaughter house close to me.
Considering you wrote “Water each layer until it is moist as you build the heap” , can I use the fresh blood to act as water/activator instead?
As a side note, I read somewhere else that you can also “boost” the composting by using “compost boosters” like Alcohol/Beer and something like Palm wine (for those in West Africa)
You can add small amounts of untreated animal products to a hot compost heap but you would not make it out of them! A pile of plant material soaked in animal blood will be just like a pile of animal blood left out in the open, it will be smelly and unhygienic and will attract flies and other pests.
The waste products from animal slaughterhouses are used to make fertilizers such as blood meal, blood & bone, but these are processed to make them safe to handle.
The only compost activators I know of are previously made compost, urine, and plants such as comfrey, nettles and yarrow. I have never heard of beer or other alcoholic drinks being used as compost activators. The alcohol would kill bacteria, which is why wine lasts so long in a bottle.
Have U considered preparing terra preta?
AFAIK the blood was one of the key substrates of the soaking process.
With biochar, it needs to used with a nutrient-rich material otherwise it will pull nutrients from the soil. Pre-charging it with organic matter such as worm castings, manure or other such materials allows the biochar to slowly release the nutrients into the soil.
I havent heard about terra preta before now, but after some quick googling, I read its mostly made of Charcoal and Compost and trace items like bone.
I didnt see where cattle blood is needed.
Can you point me to your source, so i can read more?
Hi!
I think I firstly heard of it from a site which I can not reencounter now.
I found the belows papaer at my HDD and source it was downloaded from:
https://www.researchgate.net/publication/262960183_Microscopic_characterisation_of_synthetic_Terra_Preta
I remember the pdf stated the precolombians kept the blood offering as a very very serious ritual hardly ever postponed.
I can see and appreciate their profound understending of waht they depended upond.
The biochar sponge needed to be inoculated with a reasonable amount (sizable)of nitrogen so.. here we go..more over the blood also attracted microbes..
and they did they job creating the longlastin layers of blackearth.
btw. Lastly I read taht some of organic gardeners also added dried blood to compost pile which lacks nitrogen.
btw. I justnow wrote the phrase in google which returned this https://www.amazon.com/Better-Biochar-Application-Innoculated-Biological/dp/B00INM7460
Dear admin, I want to make hot compost mainly from coir, green fodder and cow dung with cow urine. Would you please tell me the required proportion by weight and any other important technical issues.
When materials contain water, it adds weight, the more water, the heavier the materials are. Unless you know the water content percentage, it is best not to work by weight for compost materials. Which materials do you have the most of? I would use the ratio of 1/3 volume nitrogen-rich materials to 2/3 carbon rich materials. You would adjust ratio of materials depending on what you have the most of. As an approximate guess, you could try the following ratios by VOLUME – one part cow manure, one part green fodder, four parts coir. Hope this helps.
Thank you for your advice.
Just to correct myself about the compost boosters issue;
What I actually read as a compost boosters is the YEAST in beer,
It was said that the yeast actually hastens the composting process
All of my spent grain from home made beer ends in teh compost pile as the yeasty slurry do, but I doubt there is enough of survivals in it, and fresh yeast are faaar to epensive, thou the IPA smelling pile would be of great desire 😉
Thanks for clarifying, that makes more sense. 🙂
Hi Blackthorn,
Thanks for the site. I especially appreciate the lengthy questions & responses which span several years. I’ve learned as much from them as from the article, and they’ve answered a bunch of my questions and then some!
I saw that you’re into worm farming as well. I’ve had 3 small worm bins for a couple years, and have finally moved to a place with a big yard. I’m wondering how to incorporate some worms into outdoor composting.
I’ve got my first hot heap cooking (day 3, 55-60 deg C), and can’t wait to see if I can get compost in 18 days!
I’m wondering if worms would improve the quality of the compost once cooled & finished. I’ve only worked with small worm bins, so I just can’t picture them worming their way through masses of material! I’m also planning to build a bit of habitat for some worms under my cold compost bin & see how that goes.
Thanks in advance.
Briony
Hi Briony,
Use the compost in the garden, so the nutrients go to the plants. If you put worms in it, you’ll have the nutrients going to produce healthy, happy worms, and you’ll eventually make worm castings which are an amazing fertilizer!
Worms don’t need premium compost to make worm castings, they do just fine with kitchen scraps, so it would be a bit of a waste. Don’t forget, there are earthworms in the garden who will help process the compost you place there to make the nutrients more available to the plants anyway.
Regards, Angelo
PS – I ran this website anonymously under the moniker ‘Blackthorn’ – a favourite tree, because I wanted the website to be totally about giving people useful information, and not about me. This was a way of pushing back against the trend of blatant self-promotion I was seeing in the permaculture community, but in the end people worked out it was my website so I had to claim ownership of my work… 🙂
Thank you Angelo for your reply!
I’ll keep my compost as compost then.
Do you have any resources on using red wigglers outdoors? I would like to go to a larger-scale vermicomposting system than my 3 functioning rubbermaid bins…
After seeing the mentioning of compost activators, I have had a few thoughts that I wanted some input on. In regards to compost activators:
1. What are your thoughts on sprinkling small amounts of rock dust every few layers for extra area for the bacteria to adhere to?
2. In some posts, people have mentioned lightly watering each layer, in order to keep the whole pile moist. Would using a diluted compost tea as the “wetting agent” for each layer speed up the process?
As for a physical set-up for the compost pile/turn-over process, has anyone used PVC pipes as aeration tubes, to allow the aeration to happen, without turning the pile over?
Could these ideas potentially speed up the process, and decrease the manual work needed over the 18 day compost period? Or do you think it would just super-charge the pile to temperatures that would kill off all the beneficial bacteria and fungus?
Thanks for your questions, I’ll answer each in the order you’ve asked them:
1. Rock dust is a source of very slow release phosphorus and essential trace elements, great if your soil is really deficient. Organic matter in compost creates far more surface area for bacteria to inhabit, the effect of rock dust would be negligible.
2. In these instructions I mention the need to water each layer, diluted compost tea would work as an inoculant full of beneficial microbes and would definitely help get the composting process started.
3. Passive aeration using plastic pipes to allow air in would not create a fast hot compost pile, it would become a cold slow compost pile. There is no substitute for turning the compost over from the outside to the centre of the pile. Also note, the hard, white PVC used for drain pipes leaches all manner of nasty chemicals (phthalates) so I’d avoid that, you’d be better off using the flexible corrugated black plastic slotted agricultural pipe, commonly referred to as ‘slotted ag pipe’. Using plastic pipe for aeration would just create a faster version of a slow cold compost, which will take about 8 weeks at best.
The only way to speed up the 18 day compost system significantly is to use a large motorised vessel that turns constantly at a slow rate and mixes several cubic metres of material continuously for a few days, this is a commercial scale proposition and it’s not viable for a home gardener!
Awesome! Thank you for your input. I wasn’t 100% sure about the side effect of PVC, but I thought there could be some issues.
Hi Angelo, I have using your method with success! This summer, in Italy, I have had some sort of blight or fungus on my tomato plants; the leaves become spotty, then quickly die, starting at the bottom of the plant, and progressing upwards. I have been removing the dead and diseased leaves, and so far have not put them in the hot compost pile as I don’t want to spread whatever fungus it is. So my question is, will the heat of the working compost kill off the fungus? My current pile is staying around 120 – 130 degrees.
Thanks in advance! Pilinka
Thanks for sharing! The disease that affects tomato leaves is quite common, it usually happens when water splashes from the soil onto the lower leaves of tomato plants, and the pathogen spreads from there. I routinely remove the lower leaves for the first 30cm (12″) along the stem once the plants are big enough to prevent the problem. Mulching the soil well helps reduce or eliminate the problem.
Theoretically the compost in this process gets hot enough to kill the pathogen in the diseased leaves, assuming all parts of the pile get mixed properly into the hot centre of the pile. If any parts don’t get mixed properly, then there’s the risk of not getting rid of all the pathogen. If all the leaves went into the centre of the pile at the start, that would guarantee removal of the pathogen. If it’s a small amount of leaves, the insignificant dry weight you gain in compost is outweighed by the disease risk of an inadequately turned compost.
Hi Angelo,
I have just been given a big pile of grass clippings, and want to start a new hot pile. I don’t want to have too much nitrogen in the resulting compost, but at the moment all I have available to me for browns is straw and/or pine needles. I can run the pine needles and/or straw over with the lawnmower to chop them up a bit.
My question is, can I build a pile that won’t be too nitrogen rich with just these materials?
Volume wise, what proportion of lawn clippings to straw to pine needles would you suggest?
Thanks in advance from a happy gardener currently on the island of Elba in Italy!
Ciao for now!
Keep it simple, as I always say, aim for 1/3 greens (nitrogen containing) materials with 2/3 browns (dry carbon materials). In other words, add one bucket of nitrogen-rich material to every two buckets of dry carbon-containing material. This is the way of calculating it approximately BY VOLUME.
If we go into the maths to calculate BY WEIGHT:
Grass clippings 20:1, Pine needles 80:1, Straw 75:1
For the sake of simplicity, since Pine needles 80:1 and Straw 75:1 are close, lets assume 80:1 for both and err on the side of more nitrogen.
Ratio of ingredients =
[CN1 x (CNtarget-CN2)] : [CN2 x (CNtarget-CN1)]
In principle we multiply the C:N ratio of the 1st ingredient with the difference between 2nds and target, then compare it with the number we get from the opposite.
For example if were using Pine needles and Straw (C:N=80) and Grass clippings (C:N=20) to make compost (C:N target = 30), heres how we calculate it:
Pine needles and Straw : Grass clippings
= [80 x (30-20)] : [20 x (30-80)]
= [80 x 10] : [20 x 50]
= 800 : 1000
= 0.8 : 1
Therefore you’ll need 0.8 kg of Pine needles and Straw for each kg of Grass clippings, if you can weigh your ingredients!
Why the difference between weight and volume? Water content… 🙂
Thanks for pointing out the mistake, I’ve corrected my calculation, there were some rogue figures in there from another calculation which I forgot to replace with the ones in this example, shouldn’t rush these things! Much appreciated
Thanks for doing all that math for me! It’s not my forte, for sure! Curious to see what how the two different results are resolved, but infortunately I don’t have the math skills to try to figure it out myself!
Hi Pilinka, I’ve corrected the error in my calculation, thanks to papyrazzi for picking that up, all results now match up! 🙂
Hello there, thank you so much for your explanation. I’m in the progress of making it, it’s day 6 here and i just turned up the pile. I have several questions:
1. I checked the temprature using mat thermomtre and it showed 35 deg C, far from optimum temps :(( how should i do next? I just keep go on or i restart the process?
I suspect my bin is not big enough as you rcommended. I use 40cmx40cmx1m tho i only piled it until 60cm height, i guess. Anyway, here are sole technical things i observer from the 1st day-6th day
At the first day i tried to pile it in 2 days but the size goes down as i watered it. I put horse manure, veg scraps, fish bone, lots of dead snails, coconut shell, carton, wood branch, dry leafs, etc
Day 4. I found it wasn’t enough wet. I watered it well. I spotted a white mushroom in some parts at the first layer only. then i shovel it to another composter (it’s easier for me to do like this so i don’t need to shovel back inside)/and gave a good mix of inner materials are outside and outter matrials are inside the heap. The inside materials looked blacken while the rest are still the dame
Day 6. I opened my composter and pt the thermomtre, showed 30-35. Then i mixed the heap with a fourche, the shovel back to the bin. Materials underneath looked still the same (green) and the other materials still in the original form (shredded carton, snail, wood branche, etc). The size of the heap doesn’t go down. I added a bit of water because some materials looked not wet enough. I also added 1 scoop of fruits and vegs waste.
Okay, that’s it..really look forward for your suggestion, whether i continue or restart..and some technical things if i can continue. Thank you so much for your kind attention and reply
Interesting and well done. Your diagrams are very helpful. You have incorporated science in a lay persons terms to provide a script for an essential component of an (organic) garden. A few observations if I may; consider a chipper (10 hp at least) to grind material thus increasing surface area available to the symbiotic organisms (if neighbors pitch in it can be use by all and the cost goes down per member). Phosphate is important for both anaerobic and aerobic metabolism (gluconeogenesis/Kreb cycle [sorry I am a chemist]). Adding it while shredding materials will increase its volume of distribution to the necessary organisms thus increasing the metabolism which in turn increases the heat causing faster metabolism and shorter time to achieve end results. The higher temperatures will help to destroy weed seeds; adding a tarp will also cut down on heat waste along with moisture loss. Oxygen is essential as is removal of harmful byproducts of metabolism (CH4 [Methane], CO2 [carbon dioxide], NH3 [ammonia] along with other lesser known entities). H2O is necessary for the metabolism as well. Appropriate ventilation will help with all of this. Consider old soaker hoses intersped though out the pile with their perforations pointing downward. Thus allowing the gasses to escape and a means to add water. The hoses do not obviate the turning of the pile which still must be done but possibly less turning will be necessary given the other suggestions. You raise a good point concerning PVC tubing.
Is a compost bin temp. of about 30C max. hot enough to kill grass, dandilion and clover seeds in my lawn mowing?
That’s nowhere near hot enough, they survive and thrive at temperatures much higher than that as part of their normal life cycle, that’s why they’re considered ‘pioneer plant’ they can survive in harsh conditions where no other plants can to start the process of ecological progression and lay the foundations for other plants to follow! 🙂
Oh dear – looks like my best bet then is to abandon that load of compost otherwise the allotment will need even more weeding. I just cannot get the temp. any higher despite my best efforts. Thanks for your reply.
Gosh, I have read everything. Here’s my questions: I have lots of horse manure, some grass clippings, tree branches/leaves, dead cactus, lots of pine shavings used for horse’s bed with urine, straw. Please explain the portions of my first pile and when you said layer 5cm per layer, I didn’t understand since the portions of green to brown were 1 to 3. I believe the layers could not be equal height, please explain.
When it is finished, I have read that I can amend my horrible black clay soil in order to grow pastures for my horses. Please explain how to use my compost to amend this soil. Do I put it on top, do I try to rake it in and mix it (hard to do well) or????? Thank you for being so responsive to the readers. I can’t wait to try your method. Janis
As I’ve mentioned in the article – “you can work with volumes of ingredients instead to simplify things, aim to use 1/3 greens (nitrogen containing) materials with 2/3 browns (dry carbon materials). In other words, add one bucket of nitrogen-rich material to every two buckets of dry carbon-containing material.”
The ratio is one green to two brown, 1:2 not 1:3. There is no need to make layers equal height because you have to mix it all up, and you have to turn it all regularly.
To use compost, dig it into the soil, or if you’re doing a no-dig garden (see my article on this site) you simply lay the compost on the soil surface and cover with mulch.
Hi,
I have read about Berkley method just recently.
The way you have described is so easy to follow.
I am preparing hot compost next few days. I have managed to organise reasonable amount of mulch from the shredded tree branches and plan to use cow’s manure from my small farm.
In your opinion will I manage to get relatively quick compost if I spread layers in following order:
bottom only are cardboard sheets; followed by layer of mulch; layer of cows manure and repeat mulch and cow’s manure on the area of approximately 30m2 which will be sprinkled lightly with water and eventually covered by old pool cover?
I plan to test and if successful will prepare 3 more garden beds like this.
Your opinion is highly regarded
That’s not hot composting, that’s a technique called sheet composting which is the basis of no-dig gardening as I’ve described in my article “No Dig Gardening“.
Thanks for your answer.
I would like to find out what would be the difference in this case? If I understand both methods well, resulting compost is used in garden to enrich the garden bed. What I plan to do is to create one from the start using this method and enriching it further into the next season from the different compost site.
Is there a difference in quality of the end product? I want to make sure I do not “burn out” my plants and if there is anything I need to be beware of, please advise.
Thanking you in advance
HI Angelo, thank you so much for all your great work! I have been using the hot composting method with mostly great success. This last time though, after four days, the temp was a beautiful 130, the nest three turns, the pile maintained a temp of about 120 – 130, but now after the fourth turn, the temp has dropped down to 80, and I’m not sure why. Do you think it maybe go TOO hot and killed the useful microbes? Or just not enough greens? I have repiled, and this time watered it a bit, although it was still pretty moist. Now I am thinking of adding more green on the next turning of the pile, plus a little horse manure. The thing is, I don’t want to add a bunch of seeds that might get hot enough to kill them. Any advice? Thanks in advance, and keep up the good work! I’d love to come and visit your garden if I ever make it back to Australia! Ciao for now from the sunny island of Elba in Italy!
<3 Pilinka
Hi Pilinks, if the pile could down too soon it means it has run short of nitrogen-rich materials, more greens and manure required. Once the compost has cooled down properly at the end of the process it can’t burn seeds or seedlings. You’re welcome to visit if you’re ever back here in Australia!
Thanks…sigh…more green… On a bright note, I found a great source nearby for lawn clipplings. Hopefully it’s not too weedy/seedy. What I had meant to say was that I didn’t want to add a bunch of (weed) seeds that would NOT get hot enough in order to kill them. I do know that once the pile cools, it won’t burn my plants. Thanks for being here, and for the encouragement!
Hello Angelo, is it ok to post links from other composting sites? If so, can you tell me what’s your opinion in this one? http://www.gaiasguardians.info/permaculture-techniques/fast-composting/
It’s not that I’m a lazy turner, Its just that as a full time office worker I lack the time and energy for turning my compost. This is the best no turn method that I’ve researched so far, and until ClaudeA(9-16-2013 commenter) replies, I’ll go with this one for now. I’ve been meaning to try this out but decided to ask first for your expert opinion if this is plausible or not. Thanks.
Im a bit sceptical to be honest, it has its place but it also has its limitations, the laws of physics dont bend, there’s no such thing as a free lunch…
The first point, the article states this system takes 21-28 days using “shredded greens and browns”, and then it has to ‘stabilize for around 2 weeks.
Well, shredding takes work (and specialised equipment), just like turning (which only requires garden hand tools), and any composting system using shredded materials will break down much faster. I believe I’ve seen advertisements for very expensive electrically powered industrial composters that constantly turns shredded materials to produce compost in around a day! The Berkley system takes 18 days WITHOUT shredding the materials and is ready to used and ‘stabilized’ fully after 18 days. This technique you refer to is genuinely a 45-day system, and it uses a lot of props. With the Berkley system, only the ingredients are required, perhaps a tarp sheet for rainy winters.
The second point is more even more important – pathogens. A compost heap always will heat more in the centre and will be cooler on the outside because it loses heat to the outside air at its surface. By turning, you move the cooler surface material to the centre, and move the sterilized centre material to the outside, that happens with each turning cycle, to ensure that the whole lot is evenly heated to destroy weed seeds and pathogens.
Even a cold composting system will heat up very hot initially in the middle if you add enough volume of material and enough nitrogen rich material, but in no way does this ensure you have a safe compost that has destroyed pathogens, weeds and chemicals. Think for a moment that the Berkley system can break down contaminants such as diesel fuel almost completely even when added in large quantities as an experiment (people have tested it), you need prolonged, even steady heating to do that.
Like I said, the system mentioned has its merits, and may be suitable for certain applications, but is not comparable to a true hot composting system like the one described in this article. Theres no issue with using it though, I use cold composting bins, tumbler bins and no-dig garden beds that employ a sheet composting system, feel free to experiment, thats the spirit of Permaculture!
So in reality it’s just a 45 day-accelerated cold composting. I was thinking the same thing when I first read the article but wasn’t so sure about it. Thank you for clearing it up.
I guess I have no choice but to turn if I want a fast and stable compost. That 45 day period would already give me 2 batches of hot compost! Again, thank you!
Hi Angelo
I have been hot composting now for a little over a year with some good results thank you. There is one thing that is not clear to me and that is there seems to be a slant towards digging in the freshly made compost into the garden. Can it not be used in growing pots for vegetables etc, I am not sure what difference (if any) there is from commercial compost which can be used to grow most plants in containers. I would appreciate you thoughts, Thank you
Compost can be dug into the garden, or in a no-dig garden a layer of compost is placed on top of the soil and covered with mulch.
Potting medium or potting mix can be made out of a blend of composted leaf mold (tree leaves composted on their own) and regular compost – the reason being that the leaf mold improves drainage because the compost is very good at retaining moisture.
That said, after I completed my PDC, a colleague and I decided to make our very first hot compost pile using the system that Geoff Lawton taught us in class, the Berkeley hot composting method. We produced over a cubic metre (> 1,000L or 220 gallons) of compost in my colleagues tiny backyard, so he built some shallow raised beds out of recycled materials and grew all his vegies in them very successfully.
Hi,, i’m a little bit confused here. You said that “4days no turning”.
But on the “Hot Composting, Step By Step”, it said
“DAY 4
Turn the compost heap over, outside turned to inside, inside turned to outside.”
So which one is correct?
Hi Johan, I rechecked my original handwritten class notes, 4days no turning is correct. The diagrams aren’t that clear, will amend them, apologies for any confusion, thanks!
Hi Angelo, I made my first pile yesterday, unfortunately I made it only 1m x 1m x 1m. Should I go back to it and add more layers to get it bigger?? PS: love your website and knowledge
Hi Patrice, I trust it will work, especially if the weather is reasonably warm.
Hi Angelo,
Great article on hot composting!
I have a question that I hope you can help with. I have a large quantity of wood chips that I would like to compost. I don’t have a source of Nitrogen and am considering blood meal. When I look at the math of getting wood chips at 500:1 carbon to nitrogen ration adjusted to 30:1 with blood meal, I am looking at adding 50 LB of blood meal (12%N) to 180 lb of wood chips. Is that correct? Or, can I get by with less blood meal (Nitrogen)?
Hi Mike,
I’ve done the maths for you using the percentage method:
Wood chips or sawdust
%C 25-50, %N 0.1
Blood meal
%C 43, %N 13
180 lb of wood chips, 50 lb of blood meal
total carbon
Wood chips 25% to 50% x 180 = 45-90 lbs Carbon
Blood meal 43% x 50 = 21.5 lbs Carbon
66.5-111.5 lbs Carbon in total
total nitrogen
Wood chips 0.1% x 180 = 0.2 lbs nitrogen
Blood meal 13% x 50 = 6.5 lbs nitrogen
6.7 lbs nitrogen in total
depending on the carbon content of your woodchips:
66.5 : 6.7 = 9.9 : 1 (if your woodchips contain 25% C)
111.5 : 6.7 = 16.6 : 1 (if your woodchips contain 50% C)
Conclusion – way too much nitrogen!
The ideal C:N (carbon:nitrogen) balance in composting materials is approximately 25-30:1
If you use 25lb of blood meal instead with 180lb of woodchips:
total carbon
Wood chips 25% to 50% x 180 = 45-90 lbs carbon
Blood meal 43% x 25 = 10.8 lbs carbon
66.5-111.5 lbs carbon in total
total nitrogen
Wood chips 0.1% x 180 = 0.2 lbs nitrogen
Blood meal 13% x 25 = 3.3 lbs nitrogen
3.5 lbs nitrogen in total
Calculating the ratios of total carbon : total nitrogen
66.5 : 3.5 = 19 : 1 (if your woodchips have 25% C)
111.5 : 3.5 = 31.9 : 1 (if your woodchips have 50% C)
So, depending on your woodchip carbon content, with 180lbs of woodchips and 25lb of bloodmeal, you’ll achieve a C:N ratio somewhere between 19:1 and 32:1
I sourced the carbon and nitrogen percentages from University of California, Division of Agriculture and Natural Resources.
Hello angelo,
Thanks a lot for sharing berkely hor turn compost method in such detail and ease steps,this site has been an inspiration for me .I work at enactus of my college in India and we are now working with slum people to teach them hot turn composting and earn some extra income by selling the compost and all credit goes to this site for introducing me to permaculture methods ,thanks a lot buddy.
You’re welcome! It’s great to hear that you’re teaching disadvantaged people in India to make and sell compost. It is so encouraging to know that the articles and free teaching materials I write are helping people to change their lives for the better. Thank you so much for sharing this most positive feedback!
Can we do this method of compost in a big bucket? If it is “yes” …Do we require to make holes to the bucket…? Plz let me know…
The short answer is no, you around need one cubic metre (1000L) of material and good air flow.
I will write an article on how to make slow composting in containers and compost bins faster because everyone asks about this!
Hi Angelo, I have been making hot compost using your formula for a few years now, but my biggest problem has been that I have a small suburban backyard and space is at a premium. Although my wicking beds and the rest of my garden keep me well supplied with organic waste, accumulating a cubic metre takes several months. To overcome this I have built an insulated enclosure containing 400 litres, and it works a treat holding 65C for 2 weeks before starting to cool. Using this device, I can keep the bin working almost continuously so I have good quality fresh compost at all times.To aid turning, the enclosure has a removable insulated lid and splits into 2 sections to facilitate relocation.
Where does human waste belong in the C:N ratio?
Humanure 5-7% N, C:N ratio 5-10
Urine 15-18% N, C:N ratio 0.8
As you can see, urine is a very high nitrogen fertilizer!
What’s the fastest way to compost my waste, indoors?
Hello!! How about.if I will be using dried quail manure and mostly dried leaves for the composting? can you sugggest.me an ideal ratio for it?
Is the ratio 2C:1N still applicable?
2 Parts Dried Leaves
1 Part Dried Quail Manure
am I correct in this?
Hi John, 1/3 greens (nitrogen containing) materials with 2/3 browns by volume is the simple way to get the a good carbon to nitrogen ratio, so yes, that’s right! Give it a go an please let us know how you go. Thanks.
I’m so excited to have found a website that talks about the Berkley method of composting. I was a 100% sure that back when I studied horticulture at Burnley in the early 90’s, that , according to my lecturers, the best way to compost was via the berkley method, fore the many a varied reasons you have mentioned. That was 20 years ago and having forgotten a lot about how to set it up I have been trying to find information with no success. In a funny roundabout way, I’ve just discovered Pip Permiculture magazine and read a back issue with your website in it. I thought I would have a quick look and came across this section. Thanks so much for all of the great info and guidance. My next project will be to set this Berkley system up. I cannot wait. Kind regards, Kylie
It appears that I have what I need now,but I have to aerate it. Do we stillhave the PVC pipes with holes in it?
Hello again Angelo! I may have asked this before, but it seems so laborious to look through all the comments to find the answer, so I’m going to ask anyway. Please forgive if I’ve asked this before!
So – my question is this:
If my pile cools down too much after the third turning and I add more greens (in this case it will be lawn clippings which likely have lots of weed seeds) to heat it up again, should I treat it as starting over from the beginning? That is, add the greens, and then wait four days, then turn every second day for fourteen days?
Thanks in advance!
Hi Pilinka, if your pile cools down too much, and you add new nitrogen-rich material such as lawn clippings which may carry weed seeds, it is best to treat it as starting over from the beginning, because you will need to wait till it heats up again, because if you don’t wait, and turn it, it will cool back down again! So yes, add the greens, and then wait four days, then turn every second day for fourteen days?
Sigh… Thanks Angelo! On the fourth turn after adding more greens today. Temperature is maintaining so far. It seems I underestimate the greens.
Hi Angelo, first, I think it’s great that you have been replying all those questions for the last 7 (!) years, really appreciate that. My question is: I have set up a pile, which hasn’t been activated yet. Due to some space issues, I have set it up in an enclosure, made of 3 pallets. There’s no space next to it, so I have to turn the pile inside the enclosure. Is it really necessary to move the outside to the core and vice versa? Or is it sufficient to mix the whole pile thoroughly? ( which is actually the only thing I can do in my situation)
Thanks in advance
I just had someone till my garden beds and spread what i thought was composted manure. After a few days its smelly and full of flies and I’m positive the manure wasn’t composted. It looks pretty fresh. the problem is, is that it was tilled and spread into my new garden beds. I wanted to have a vegetable garden this year but I’m worried that there may be too much bacteria and pathogens present that haven’t broken down yet. Do you have any recommendations on how i could speed up composting process with manure that is already spread in my garden beds?
Thankfully the solution is quite easy, since manure, especially fresh manure, is very high in nitrogen, all you have to do is cover your garden beds with a nice thick layer of carbon-rich material to get that C:N (carbon:nitrogen) ratio of 25-30:1 and the soil bacteria will quickly use up the manure to make a nice, rich compost.
Adding a layer of carbon-rich material is simply mulching, covering the soil with about 5-10cm (2″-4″) of straw (pea straw, lucerne, sugar cane mulch, etc). What you’re doing here by laying mulch over manure on the soil surface is no-dig gardening, (which is really ‘sheet composting’) follow this link to see my article on the subject, it’s easy and works well!
I cant spend most of my day looking for an answer over 4 to 5 years, so i will ask and apologize if already answered. if i can add a dead animal to a hot compost pile can i then add poop from one dog and three cats? and what about the litter used for the cats? how much of the poop do i need to collect first, before starting the pile? My regular compost consists of kitchen scraps – including daily additions of eggshells and coffee grounds; clippings and weed pulls; shredded paper and egg cartons; and avocado tree leaves. once a month i char fish and chicken bones and pulverize to add to the garden or mix with soil for alliums. Maybe I should just throw in the compost. I also pulverize a large bowl of eggshells from a friend to amend mandrakes in bags. I will add that i live in Ecuador, where it gets very hot between 10 a.m. and 4 p.m. My compost pile is on a concrete pad that gets sun most of the day and is turned every three days for a handful of compost for the “Tea” that i use as liquid fertilizer thru’out the garden.
Putting ‘road kill’ dead animals in the middle of a hot compost pile is done quite often. That goes right in the middle where it gets hottest first. Only do that if you follow the method as I’ve described it which keeps the compost heap hot for a very long time, killing any pathogens. If you’re not following the instructions and turning when you choose, which you are, then don’t use dead animals, you’re asking for trouble.
Dog and cat poo in your compost, certainly not! Manures and other nitrogen containing materials need to be spread right through the hot compost heap, so if you spread dog and cat poo through your compost heap, the cooler outside parts would be extremely unhygienic and spread diseases, it’s not worth it!
Hi Angelo, I love your blogs since I read it over 5 years ago! I often reread or refer to it, and have told others about it. I received a whole bunch of hay a few weeks ago, but it’s full of weed grass seeds, as I wanted to use it as mulch 🙁 I have been trying to hot compost it since, and mixed some layers of bought compost, my own compost, some green weeds and other kitchen scraps. At stages, it got warm, but it keeps cooling off and was stone cold when I turned it last…what am I doing wrong? Is it the balance of green/brown? If I added horse manure, will that help (as I’m getting some hopefully this week)? I just need to get it warm enough to kill the seeds as I don’t want to spread it around the yard unless I have. Any advice appreciated.
If the hot compost is cooling down, you don’t have enough nitrogen rich materials, adding horse manure will definitely heat the compost up!
Thank you for this wonderful post. I have a big garden and lots of composting material. I will certainly try to make compost this way.
HI
Great site & article’ full of useful info. I’m looking to grow some small herb plants indoors and having seen how much compos costs, I’d like to create my own. However, I have no garden so Im looking to do some indoor composting. One question , is iindoor hot composting practical ?
Hi, you can grow some herbs indoors, but these need to be planted in a potting mix or potting medium, not in compost. Compost is sold very cheaply, around half the price of potting mix.
Composting is basically aerobic bacterial decomposition of plant matter, not the kind of thing you want to do indoors! Composting is for plant material and tree prunings, if you don’t have a garden where will this material come from? If you have only kitchen scraps and newspaper, then you may be able to process these in a worm farm (a bit questionable indoors still, maybe in garage or shed) or even better, in a bokashi bin which you can keep in your kitchen!
Great article! Composting is great method to growing organic garden. I also dont want to use other fertilizers
I get turning the stack over to add oxygen. What if I would put perforated pipe every so often in the stack and pump air into it every couple days instead of going through the work of turning it? I realize the outside would not compost as well, but I could use that in the next stack with far less work. Do you think this is a viable option?
Turning the compost heap to add oxygen is only half of the whole picture.
Turning the outside of the compost heap to the inside:
1. adds fuels to keep the composting process going
2. keeps the heat up
3. puts all the uncomposted material in the hottest part of the heap.
Is it possible to use the ‘Berkley method’ for hot composting in a compost bin smaller than 1 or 1.5 sq meter ( for example 2 cubic feet) ? To compensate for the lack of heat generated (as in a big pile) can we use a heat source core ( like embedding a small plastic water tank with water heated by a solar water heater upto the required 65 C). Trying to come up with a way to do this in an apartment balcony / patio on a smaller scale…
The Berkley hot composting method will definitely not work in a small volume container. The heat is not what makes the pile turn to compost, the heat is created by the composting bacteria when they break down molecular bonds in the composting materials and release energy. To create compost, the bacteria need the material turned often to supply them with fresh material to consume and fresh air for oxygen supply.
What the heat does is kill the bad bacteria, pests, weed seeds, fungal diseases and break down harmful chemicals. The bacteria in hot composting are thermophilic bacteria, they live and function at high temperatures.
Composting is a complex subject, industrial kitchen waste composters use a large drum that is constantly rotating at a slow speed, not sure if you want a machine continuously running indoors or on your balcony.
Remember, composting is for garden plants waste, prunings and clippings, and hot composting will produce 1-1.5 cubic metres of compost! Now, I can’t imagine that a balcony or patio garden will produce much garden waste in the form of leaves and branches, nor will that volume of compost be usable.
I would imagine that a person with only a balcony or patio will produce kitchen waste, which would be far better processes in a worm farm. See my article on worm farming for more information.
A better option for indoor kitchen waste processing is a bokashi bin which is worth considering.
Does rotted manure have the same C:N ratio as fresh manure? I only have rotted manure which I intend to use in my fall hot compost pile.
Fresh manure contains more nitrogen but rotted manure is perfectly fine as a nitrogen source for hot composting.
Hey Angelo,
Just wondering whether this process could be accelerated further by adding heat at the start to get to 55-65 degs quicker. I’m thinking less in terms of home use and more in a commercial sense where waste industrial heat could give it a ‘free’ boost.
cheers
Nathan
Heat is a by-product of the process, not the driver. What drives this process is fresh material and oxygen being made available to the composting bacteria. Commercially they create huge rows and turn the composting material daily with heavy earthmoving equipment, or build they build giant drums that continuously rotate at a very slow speed to mix the materials and let in lots of oxygen.
thanks.
Another thing, would adding heat at the start help get the end product to a higher standard? Ie we have 3,000,000 tonnes of compost from Melbourne Water sewerage but no one will touch it so it keeps accumulating. Can heat be used to treat the pathogens the farmers are, rightly so, cautious about?
cheers
Nathan
No, adding heat would interfere with the natural progression of various kinds of decomposer organisms that takes their turn in breaking down composting materials at lower temperatures before the thermophilic bacteria play their role.
I believe many farms use their own sewage treatment, using anaerobic digesters that then feed into aerobic digesters, which finally run the nutrient rich waste water below the soil to feed orchards.
Big cities have sewage treatment plants to handle the large amount of waste, unfortunately, the effluent is dumped into the ocean at the final phase, causing eutrophication that results in toxic algal blooms, etc and resulting in a net loss of nutrients from the soil to the ocean, but that’s a whole different story.
By composting any garden waste, we return the nutrients back in the soil, where they belong!
Excellent blog!! I impressed your blog, you explained wonderfully here about the composting system. I like your method.Thanks for sharing this technique.
I do appreciate it. It is wonderful and can make me rich through using it on my farm which will cut the cost of production as purchase of chemical fertilizer is eliminated.
You haven’t mentioned the compost making whether it’s on the ground or duh in pit of 1.5×1.5 metre put ???
Kindly reply
This type of composting requires air, so on the ground, not in a pit.
Thanks for describing very well the process of composting the Berkeley way. In your blog, the critical variables of C:N, pile size, building method by careful layering and even water saturation, and the monitoring and managing of core temperature to 55-65C by turning the pile to release heat are nicely covered. There is one variable not mentioned which recently came to my attention because of the failure to reach pasteurisation temperature in a new client’s compost pile. What does not seem to have been covered is the porosity or air spaces in the pile. Thermophilic bacteria require oxygen to become active and multiply and if the pile is comprised only of small particle feedstocks with little airspaces or if the pile has been physically compressed, the desired temperatures will not be reached. Have you had any similar experience that you can comment about this? Also, with a good C:N and pile build the core temperature should easily attain 55-65C in 4 days. Whether it will again reach that range of temperatures because of turning every 2nd day thereafter makes it difficult to understand how the whole pile can reach pasteurisation for 3 days as the composting standards state. Have I missed something here?
Additionally, as much as the end product after 18 days may be considered a quality compost by going through a thermophilic decomposition which deals with plant propagule and disease carry over, it has a very narrow range of active microbial diversity without going through a maturation phase. The maturation process takes the secondary metabolites from the thermophiles as food for the dormant but ready to sporulate higher order microbes resident in the compost which then releases the full potential qualities of the final product.
Please keep up your great work – it is essential that more people understand the unrealised benefits of microbially driven and managed Soil Health, Plant Health, Animal Health and Human Health as once living materials are cycled through the enhancement process of well managed thermophilic composting.
Thank you for the valuable information. I have a question; will it make a difference if I use fresh or old manure? Which one is better? Thank you!
Both fresh and aged manure can be used in hot composting, fresh manure has a much higher nitrogen content!
My dad uses this method of composting! Best part: if you do the ratio’s right, there’s no stink. If the compost pile is smelly, you’re doing it wrong.
I have a few questions, I am new to composting and I really want to try hot composting! Partially because I feel like my husband and I have so much food waste that could be turned into soil for my upcoming garden! I know that I currently don’t have enough materials to start this kind of compost, so I am thinking of getting some larger forms of brown compost. When you start turning this compost, can you add more to the pile or do you need to start another one? My other question is does your compost piles have something around them to hold them in that specific place? I have two pups and I don’t really want them to start digging in the pile. Speaking of my pups, can I put their waste into the compost pile as well? I also really appreciate this post explaining hot composting in a much clearer way than other things I have seen!
Now we have a microbial technology where contains consortium of Local micro organism. They have capability to fermented cow dung without produced methane gas, hot and smelt , and then directly use for planting. We have introduced to get practice in community of farm that make fresh cow dunk in bracket form. It just need 2-3 days to dry…. We will to share for Who is interested with. Thank for your attention.
Excellent article. Thank you. I am very interested in the whole composting process. My main question is about disposable coffee cups really. Have you tried throwing them in too?? I have heard they have to be hot composted not cold , which has thrown a lot of consumers. Do you have to mulch them first or can they be whole and act as oxygen bubbles in the compost??
I haven’t tried biodegradable coffee cups yet. They’re made of cardboard and lined with a plastic Polylactic Acid (PLA), which is made from corn starch. It is a stable plastic that doesn’t break down in a regular slow-cold compost bin. PLA can break down when processed in commercial compost facilities where the temperature reaches 140 degrees F (60 degrees C) for ten consecutive days. Since hot composting maintains temperatures close to this level for much longer, PLA would break down in a hot composting system.
Hi, Thank you for all your wonderful information. Trying hot composting. Wanted to ask if I can compost bamboo leaves, I heard they slow down the plant growing.
You’re welcome! Many bamboo species produce allelopathic compounds which inhibit the growth of other plants, and I’m not sure if these compounds would survive hot composting.
If you’re interested in which allelopathic compounds are found in bamboo leaves: “o-hydroxyphenylacetic,p-hydroxybenzoic,p-coumaric, vanillic, ferulic, and syringic acids were found in the aqueous leachate and extracts of leaves and alcoholic soil extracts of Phyllostachys edulis”
Source – Journal of Chemical Ecology,December 1982, Volume 8, Issue 12, pp 14891507, Allelopathic research of subtropical vegetation in Taiwan II. Comparative exclusion of understory by Phyllostachys edulis and Cryptomeria japonica Chou, CH. & Yang, CM. J Chem Ecol (1982) 8: 1489. https://doi.org/10.1007/BF00989105
Thank god finally someone who knows how to compost. This is a breath of fresh air.
I believe you are wrong on a few points, but overall great article.
The points i wish to make are:
1/ ratios are not that important. They give bulk and speed.
2/ water is what makes composting smell. Not just added water but water in the ingredients. Eg. Get i ton of fresh tomatoes put them in a pile and they will stink to high heaven. Pulp them spread them out to dry to 50% moisture . You end with 500kg. Now pile them up and aerate and they will compost and not stink. Understand it’s not the ratio it’s the water.
3/ methane is produced in absence of oxygen. Good composting is aerobic so methane cannot be produced.
4/ temperature is govened by oxygen, in a compost pile at the correct moisture content. The temperature will start to fall when oxygen is depleted, that should take place on the third day. This the day to turn the Compost.
5/ put a steel rod in the centre of the pile if you can hold it, then its not hot enough. Or use a thermometer, the temp should be between 60c to 70c. The bacteria we want love this temp. Over 75c those bacteria will be replaced by bacteria that can take the temperature to 400c these are not the bacteria we want.
6/ do not go over 1.2 metres high because the weight of the compost will smother the bottom of the pile.
7/ do not feed worms from your compost. Worms are high in protein (nitrogen) so they ate stealing your hard won compost to feed and breed. The compost you want for you plants. Unless you want to catch and grind them up for your plants. Just don’t let them carry it away.
8/ never add to your pile once iy is started. When you add to the pile day one starts again. You will start to lose kg’s from going longer. Too much water is very bad and costly mistake.
9/ if you can squeeze any drops from the compost it’s too wet.
I never manage to get hot compost going and inevitably try to rectify the heap by breaking it open and adding more material, as I don’t know why the original heap didn’t heat I have no idea what to add, so start the failure all over again! I currently have four such failed heaps (usually I end up spreading or burying them in the autumn on the bean patch to be). I have been doing this all my garden life!
I also have three gooey wheely bins full of kitchen vegetable waste which I also end up “trenching”. In desperation, this year, I set up a wormery to make the end product less unpalatable. I have a very good productive veg patch but I would like to produce some compost to use in my seed potting mix – hence the hot compost attempts.
I despair that I keep getting told it is easy :).
Out of interest, if you had a heap that failed to heat what would you do, assuming it is not too wet? How would you decide what to add?
If your compost heap is not heating up, and it’s not too wet, then you don’t have enough nitrogen-rich materials!
Worm farms are a great way to process vegetable and kitchen scraps, see my article – Worm Farming
Hello Angelo, Thank you very much for the original article, and having the patience to still be answering our questions!
I’m convinced that Bokashi bins are the way to go regarding kitchen waste scraps, and I’ve seen you advocating this several times above, and I’ve seen your other article about it. My question is: am I correct in thinking that the “pickled” kitchen waste from the Bokashi bin, when it has been left for the requisite time, is a good compost activator?
Is the same true for the liquid runoff from the Bokashi bin?
Many thanks in advance.
hi. I have made quite a few hot compost heaps, and i love the process. however sometimes the pile does not cool after 3 weeks. what causes this, and what should I do? thanks for your help, Jon bridges
That sounds like you have too much nitrogen-rich ingredients in your compost. Try adding more carbon-rich dry materials. Is everything completely broken down and unrecognisable after 18 days?
If everything looks like it has broken down after 18 days, you can let the compost heap cool down on its own.
Thank you so much for this, I am on a roll, madly looking for thing’s to pile into my compost heap. Brilliant! Finger’s crossed I do it right, desperate for compost as I live at the beach and the soil is so sandy, water just pools and runs off. Thank you for sharing ??
Thanks a lot , for complete guidance to a layman . Farmers can reduce the input cost and can survive naturally.
Can you use algae as brown material?
They contain ALOT of carbon and can be dried.
Yes, or used fresh as green material.
I am collecting waste vegetable and hotel waste from my nearby shop and hotel and put it in a compost tank of 5 feet long, 4 feet breadth and 4 feet deep. Alternatively, I am putting cow dung, some soil and spraying little water on the top of the layer. Will it becomes real compost?
Vegetable scraps and manure are all very nitrogen rich materials, you’ll need to also add some carbon rich materials as listed in the article to get the right carbon to nitrogen ratio.
It is good to post this things, but there is a warning missing:
Don’t use this compost with youn plants or for potting plants or with bare rooted plants, because it is not ready yet.
The rotting still keeps going – it is still warm.
So there are some organic acids produced wich hurt the roots of plants. If you wait additional 4 Weeks ist will be ok.
If you only use this compost for mulching it is also ok. Or if you mix 1/4 of this compost it with 3/4 soil it schould also be ok, for elder plants, but not for seed and young ones.
Take care of your plants.
When using compost for planting I would recommend using no more than 1/4 compost when mixing it with soil in the hole for planting up new plants or trees. Same with rejuvenating soil in a raised garden bed. If too much compost is used, the compost will settle over time and the planting level will drop. Having a raised garden bed soil level or tree planting drop lower down is never a good thing!
Hi this is very useful article, thank you. I am following this method with a heap made from layers of fresh horse muck/cardboard/spent hops/cardboard/repeat. What is the expected temperature profile over time? I get up to about 60c by about day 5 then start turning the heap. In current heap, temperature has dropped to 35c on day 17. I didn’t turn it for 5 days (days 11-15) as I was away on business. The compost no longer smells sharp and is dark but I don’t think it’s fully broken down. Should it still be hot? Do I not have enough brown in the mix? Or is it just ready?
Thanks in advance for any advice you are able to provide.
You’re welcome! This process only works if you follow the instructions. Bast to start over, adding the incomplete compost to the new mix to break it down completely.
Sigh. Ok. I will get some fresh material. I don’t think i had enough brown in the mix, i had more like 2:1 instead of 1:2. Also some of the cardboard was glossy on one side, that hasn’t broken down well. I also didn’t cover it and rain got in, perhaps that cooled things down too.
Can I use older kitchen scraps or older garden waste in this method? I am thinking it will take me a while to collect enough for the size of pile required.
Add any organic matter that you may have, if it was once alive, it can be composted. Just be aware that if you keep kitchen scraps or green garden waste for a while, the nitrogen content decreases, so you lose nitrogen. I prefer to put kitchen scraps in a worm farm – https://deepgreenpermaculture.com/diy-instructions/worm-farming/
Very well explained. Thank you 🙂
I need a couple of clarifications and advice.
1) What if i replace turning with passive aeration – veritical perforated 4″-6″ PVC pipe in the middle of the pile – 4′ x 4′ x 4′. Labour is quite expensive now-a-days.
2) What if keep adding to the pile as and when i get the material. I may not have enough to start right away. But build it up in say in a month, adding whatever kitchen waste i have daily, garden waste like grass clippings and prunings once or twice a week etc.
You’re welcome!
Passive aeration will create a faster version of cold slow composting system, that’s a completely different type of composting system.
Slowly adding ingredients will create more of a cold composting system once again as there won’t be enough materials to create the critical mass to get the heat levels up high enough and long enough.
Maybe I should post up some other composting systems which you might like.
I add my kitchen ccraps into my worm farms, they are great for processing a steady stream of small volume food waste – https://deepgreenpermaculture.com/diy-instructions/worm-farming/
Thank you for sharing this article. I am doing my hot compost now and want to share my experience especially because I did few things on a unique way. I selected the place under a huge pine tree because the pine leaves never let the rain water in. So is dry and gets a bit of sun but is December. I couldn’t manage to have all the ingredients I wanted to put in from the first day. I needed to cut grass, mulch Laurel leaves which is the hedge. But little by little I cooked up my compost like a meal. I tried to balance the greens and browns. Added horse and chicken manure with straw. I added water at every layer. However I found at every turning that is just extremely dry. It reached the temperature of 55-65. In the meantime we had a dead chicken, a dead rat in it. They all disappeared for the second turning. The chicken just vanished. No feathers, no bones, no bits left.
Now the compost is quite homogeneous however I found it too dry so I added some horse and chicken manure and some water. Each turning cooled down the temperature to 30 degree C. Them goes up again. So all is doing well however is a bit slower the process. I am possibly on day 20 and looks all like day 10. Size is 1.5 m and yes I turn it every second or 3rd day, smells good. is nice and hot. So what is the best way of using it when is ready? Shall I let the chickens to eat the worms up from it? I guess is not a good idea? Shall I just turn it into my vegetable garden? Shell I use it for nursery as well? Thanks a lot.
Hi Eva, thanks for sharing your experience, quite amazing how a whole chicken can break down so quickly in a hot compost pile!
Even though your compost seems to run dry quite quickly, it appears to have worked, well done! The best way to use all that wonderful compost is to dig it into the garden, or if you’re doing no-dig gardening, just lay it on the soil surface and put a nice thick layer of mulch around 7cm thick over it and let the earthworms dig it in for you.
Disappearing chicken… foxes will bury chickens if they can’t eat what they have killed all in one go. Was the chicken removed by a fox?
Excellent Article….what changes do I have to make if I have to give access to chickens??
I’m not sure I fully understand the question, would the chickens need to access the compost heap?
Would fresh cut Lucerne hay be in the green or brown category?
Fresh cut lucerne is definitely in the green category, while lucerne bails which have a bit of a green colour to them are perfectly balanced in carbon and nitrogen, so they’re both green and brown at once. If you leave a lucerne bail in a container, it just becomes compost on its own.
Great article. Do you have a reference for the work done at Berkeley or any further papers on this subject? Thanks
Thanks for you comment Bruce! I was taught this technique by Bill Mollison and Geoff Lawton when I studied with them to complete my PDC in 2008. The technique has worked brilliantly for people worldwide from the feedback I’ve been receiving over the last decade.
As a technical writer with a science background, part of my skill set is to be able to explore scientific literature, identify relevant scientific publications and research, and then translate the content into plain English so regular people can understand what it means and apply it in a practical way in their lives. I include sufficient scientific background information to give explain the ‘whys’ and provide context, while focusing on the technology, the ‘doing’. It takes a lot of effort to get scientific data into usable instructions for gardeners, and you’ll find lots of this kind of information on Deep Green Permaculture.
The original source material is hopefully still lurking somewhere on the Berkeley UC website. Linking to such source material is problematic for web authors as many universities and government organization change their websites around, remove or archive content, leaving lots of dead links in sites that link to their content…
Thanks for the article , I like the fact you are still replying to a thread so old. My Question is about comfrey , I am growing a patch especially for composting but it says to use it as a starter. This makes me concerned about using it in bulk as greens , would it be too heavy on the nitrogen or can I just use more browns , I have limitless access to fine mulched woodchip and stable straw mixed with horse manure. can I still use the 2:1 brown/green rule of thumb? Thanks again for your sites patient approach to bad mathematicians.
Very useful info.I am a lifetime organic gardener from UK. I am wanting to help transform waste disposal methods here in the home of my extended family in Cirebon,West Java,Indonesia.
The destruction of the ecosystems of this planet are so painfully displayed here in Indonesia,and I am desperate to find solutions that will work to transform people’s lives ,especially the poorest who live amongst the mountains of garbage and suffer the toxic effects most acutely.
I have spent much of the past 15 years involved in a poor community by the sea , a section of the town known as Pesisir Selatan that has suffered severely from a multitude of urban changes including coal dust pollution from the adjacent port, coal and oil pollution from many sources, and the completely uncontrolled explosion of plastic and other non biodegradable waste that pours into the water systems that drain to the South China sea, or pile up in toxic mountains everywhere.
The need for the education of the people from early ages upward,for massive local and national initiatives to provide for waste collection, sorting and recycling , and the need for a plastic solution is now so blatantly obvious that only a strange distorted working of the human mind can explain it!
I have so many answers but I am one person.
Is there anybody out there?
….just to clarify the intention behind my comment…how to utilise the composting method you describe and apply it in an urban (semi urban?) area such as this, how to make it work from an economic veiw point so that the value of the work involved is understood, and include it in the wider scheme of sorting all waste and initiating change.
Your description of composting was the most dramatically rapid and potentially lucrative I came across.There is unlimited sun and much water here and a great need for unprocessed food amongst the poor who are many.
As the solution to plastic appears close,(I am led to believe) the heart of this community seems like a perfect place to initiate a possible “clean” revolution in S,E.Asia.More qualified experts than myself are needed to communicate with government at whatever level.I can give feedback from the grassroots level and pass it on upwards.
That was my meaning of asking if there were people involved in composting who had an interest in the effort to help to start to clean up at a global level,working outwards from a “black spot” to create a model to work from.
Hi
This is the best informative article about hot composting on the net. Thank you very much. My concern is about the Carbon-Nitrogen balance. If I use fruit waste (35:1) I am already at the right C:N ratio. It seems I don’t need to add something else. Am I right?
If it is still recommended to add to the fruit waste some “browns” which will turn the mixture to a high carbon mixture, will you recommend adding a substance containing high nitrogen like diluted urine (1 to 5) as the Berkeley method mentions?
The fruit waste has the right C:N ratio for bacteria to break it down, it will break down very easily for this reason, but it holds too much water, and will become a soggy mess which will not allow any oxygen to get into the mix, it will begin to ferment, which is anaerobic decomposition, so you need to add dry material (these are usually high in carbon) to take up water and create air spaces. When oxygen can enter the compost mix, aerobic composting can take place.
To further illustrate the problem with wet vs dry materials in composting, if we compare the wet fruit scraps to a bale of lucerne we see a huge difference. Lucerne is almost at the perfect C:N ratio also, but is dry, and if you leave a whole bale of lucerne in a container and moisten it slightly, it will become a pile of nice compost because of its ideal C:N ratio and because it’s a dry material which air can get through. Obviously, this would be slow composting, which would take a while, and the resulting compost will only be 20% of the volume of the original material, but this is just to explain the point.
Hi,
I’ve been making hot compost for the past 20 years or so in bins about 3ft cubed.The compost heats up in the centre to 70 degrees C sometimes within 24 hours but, at that temperature, the compost dries out very quickly. The top is wet, where all the moisture has condensed, and underneath is almost ‘crispy’. I cover it with Coffee sacks which start off quite light in weight, but then become very heavy with the steam that has risen up. When I give the heap its first turn in about 3-4 days, I have to go over it inch by inch re-wetting it all. Is there any way I can prevent this?
Hi Mike, the compost is overheating because it’s in a bin, and it’s getting dry because it’s getting too hot and the water is being lost as steam. The enclosed sides are retaining the heat and directing it all upwards, hence the heavy condensation.
It should work better as an unenclosed compost pile, it won’t get as hot and retain moisture much better.
Hot composting what could be cooler right? The carbon to nitrogen chart is very cool but I was wondering ….(for conversation) how do we determine the amount of nitrogen (and carbon) that these compost piles extract from the air?
And if you have already discussed this topic above..my apologies..
Thanx for the article
Ed..
Hello.
I have had great success for many years using your method.
Large, small and huge have all created beautiful compost.
However this time i can`t get a compostheap going, albeit it is indoors and smaller it should atleast increase in temperature.
At this point i have done all the troubleshooting you mention, yet it doesn`t even slightly heat up.
Coffee grounds and cardboard has been the main ingredients in the right ratio…
Could it be chlorinated water ? :O
There is a critical size for a compost heap that will generate heat and retain it, then continue on in thermophilic mode.
If it’s too small the heap dissipates too quickly, or there isn’t enough fuel to keep it going so it heats up a bit then cools down.
This is an extremely helpful article! I have a question about the practice of covering and turning though. Im working in community development at the edge of the Sahara desert and someone from another part of West Africa taught me a 21 day compost method, but now Im trying to understand why it works. I learned the same ratios you give and the need to get the compost fully saturated with water (3 measures of Dry Plant material, 2 measures of Manure, 1 measure of Wood Ash). But I was taught to put it in a seal-able plastic feed-bag or bury it underground with at least 10 cm cover to keep air out. Plus I was taught that you leave it to sit for 21 days without any turning or changes. Thirdly, most people are doing it in a 1x1x1m area or smaller, to use on gardens, although some are doing it on a large scale for partial field coverage. What mystifies me is that weve now been teaching it to people and everyone has good results, but I dont understand why as it is contrary to most of what Ive read about composting. Id like to know if were just getting sub-par results because of bad teaching but people think its great because the soil is normally so poor? Or if some of these modifications might actually be helpful for our hot, dry, sandy, devoid of nutrient soil?
Hi Michael, thanks for your comment!
The 21 day compost method you mention sounds interesting. Makes sense that the carbon to nitrogen ratios are similar to the ones I recommend, that’s a necessity for efficient composting. If you’re not turning it, putting it in a sealed bag, and burying it below the ground, that sounds like an intentional effort to keep oxygen OUT, which would make it anaerobic composting (as opposed to the goal of the 18 day aerobic hot composting method to maximise oxygen availability to the compost material).
I must ask, using your method, which sounds like an anaerobic system, does the volume of materials decrease when the composting process is finished, like what happens in slow composting? Also, how does the freshly composted material smell, is it pleasant and earthy of a bit sour smelling initially?
If your method produces good compost in an area where the soil quality is poor, then what’s important is that you’re improving soil quality and growing more plants in such a challenging climate.
Presumably it’s the effect of the ambient temperature, it makes sense that if you put the mix in a sealed bag in a very hot position it will do the same as it would if it had to raise it’s own temperature, but do it quicker? Also, do you seal the bag with air inside, or has the air been pressed out?
As for working while buried, I would be interested to know the ground temperature, maybe in a light soil there is enough oxygen and heat at the location
Hi Michael – I was in the area of Goulmim, Morocco, and hoped to find some communities interested in soil restoration using permaculture techniques and found none 🙁
Where are you based with your project ?
Wow, nicely explained!
How do you explain that with cold composting the volume reduces, while with hot composting the volume stays the samen?
Thanks very much!
With anaerobic composting (composting without oxygen), which is what happens in cold composting when a pile isn’t tuned much, a lot of material is lost to the atmosphere as it breaks down.
In an anaerobic compost pile organic nitrogen is broken down into to organic acids and ammonia, and a major portion of carbon is released in the form of methane gas (CH4) and a small portion of carbon is respired as CO2.
maybe also the hot compost doesn’t compact as much because it’s turned every 2 days?
Actually, the reason why a hot composting heap doesn’t compact is because the composting process is aerobic and uses oxygen, whereas a slow composting heap runs out of oxygen easily and starts breaking down anaerobically (without oxygen). The slow composting process changes the chemistry of the composting to one where a fair bit of carbon and nitrogen is lost to the atmosphere, so a lot of the nutrients literally evaporate away, which is why slow compost heaps reduce down to 20% or original volume while hot composts don’t really shrink at all. ?
Hi. Love the article, and having a great time working my way through the comments! I have a question, if I may : youve addressed the method of adapting to a cold environment [the West of Ireland], but how does one adapt this method to composting in a hot country? Im exploring the idea of composting in Lebanon, where the summers can be intense. Obviously, I dont want compost piles to become a fire hazard, so does anybody have any tips for keeping the heaps warm enough to work efficiently, but not so hot that they burst into flames? Many thanks in advance. ?
By keeping the composting materials slightly moist as described in the article, the bacteria can perform their work more efficiently, the evaporation keeps the compost cool, and the water content prevents any fire risk! ?
Hi, brillant article! I have a couple of questions:
1. Can you make a smaller pile work if you insulate it with blankets, straw, etc?
2. Are there diagnostic signs for whether the pile has too LITTLE nitrogen, so I can add urine etc?
Thanks!
Hi Robert, the instructions give absolute minimum requirements for compost volume and compost turning, any less compost and it won’t work as an 18 day hot compost, it will be a slower cold process instead.
To answer your second question, it’s easy to tell when your compost is too low in nitrogen – the compost pile cools down, and the woody or dry materials doesn’t break down. Adding any additional nitrogen-rich materials, including urine, will help fix the problem.
Angelo, I just got a load of green wood chips. Your list says green wood is high in nitrogen and chips are low. Which is it?
That’s an easy question!
The confusion arises because in sawmilling and timber production, green wood refers to timber which has been recently cut and still contains high amounts of moisture because it has not been seasoned yet. That’s not the botany definition though…
Green wood is young or juvenile wood, it’s the soft, sappy growth which has not hardened off yet to become fully woody and brown. Typically the type of new season’s growth you see at the tips of branches in late spring to early summer.
If you consider ramial chipped wood (chipped branch-wood), which is made from branches less than 7cm (~ 3″) in diameter, it’s much higher in nitrogen than wood chips made from thicker branches or the trunk of the tree. As tree branches increase in thickness, the nutrient levels decrease. Ramial diameter wood is high in nitrogen and has a carbon to nitrogen (C:N) ratio which averages 30:1, where trunk wood contains very little nitrogen and usually averages a C:N ratio of around 400:1.
Hello Angelo, thanks so much for the excellent article. So am I sadly right to assume that youre saying composting in a big tumbler can never truely be hot composting?
Hi Anne, that’s correct, any domestic composting tumblers available to home gardeners are just more efficient cold composting systems, they can’t maintain very high temperatures of 55-65 degrees Celsius for 2-3 weeks because they don’t hold enough materials to maintain the heat and keep fueling the hot composting process. There are giant industrial versions of tumbler composting systems that are motorised and turn on their own continuously until the compost is ready, but they’re enormous in size, use lots of power and very expensive.
Hi. Thanks for the great article! I am a bit confused by the dates:
DAY 1 Mix together ingredients
DAY 5 Turn the compost heap over, outside turned to inside
Turn the compost heap over every second day (on day 6 and again on day 8).
**(Wouldnt 2nd day after Day 5 be Day 7, and then Day 9 as it is stated later in article?)
Day 7 & Day 9 turning compost
DAY 11 to DAY 17 Continue to turn the compost every 2nd day
I guess my only confusion is the inclusion of: “(on day 6 and again on day 8).
I accidentally turned on 2nd Day, misremembering instructions Maybe I should now consider that 2nd Day as Day 1 and wait 5 days? (Then turn every other day.)
I also have trouble keeping it cube-shaped; it keeps getting cone-like and stuff (horse manure) keeps rolling off.
Thanks.
I also have trouble keeping it cube-shaped; it keeps getting cone-like and stuff (horse manure) keeps rolling off.
If you make the base wide enough, around 1m wide, you should be able to get it to sit reasonably flat at the top, it doesn’t need to be a perfect cube, but don’t make it a narrow pyramid shape either.
I have successfully gone through my Berkley compost experiment except for the fact that my materials are still identifiable upon close inspection. I only used grass clipping and some leaves. I had to add more dried grass at some point which I think is the reason I have some identifiable grass and leaves. What do I need to do to further heat up the heap. I was thinking of putting the dead bird from my garden or fish bones but I dont want to make a mistake here. Any advice to a newbie to composting altogether, I have difficulty in working with the numbers and generally learn well when I do the job. Thank you for a fantastic website, I think Ill be studying many of your ideas. Writing from Johannesburg South Africa ???
Thanks for your comments Portia. Your compost won’t heat up enough because you really need some high nitrogen materials. The grass and leaves are already at the optimum C:N ratio of around 30:1, so adding any dry (high carbon) materials will just increase the C:N ratio, reducing the effectiveness of the composting process. Do you have any materials very high in nitrogen, such as animal manures? They will work really well to get the compost cooking!
Hi Angelo. I’ve built my first compost heap and we are on day 4 @ 71 deg C. Your guidelines suggest this is too hot, but UC Berkley article says it is optimum. On day 2 and 3 turns I noted a slight ammonia smell, so corrected with sugar cane mulch and charcoal dust (not ash, just pure carbon charcoal dust from bottom of my charcoal bin for the bbq). This morning it is back up to 71 deg C. Should I just let go and keep turning each day?
Hi Luke, your compost is way too hot! According to Cornell University Waste Management Institute when managing the composting process you should aim to keep the compost below about 65C (149F) because hotter temperatures cause the beneficial microbes to die off. If the pile gets too hot, turning or aerating will help to dissipate the heat. I wouldn’t add charcoal as a carbon source because the composting bacteria can’t use it, they only use organic compounds, complex carbon-containing molecules as their carbon source. When they break these compounds down, they release the energy from the chemical bonds to create the heat in the compost.
Washington State University Extension also states that the optimum temperature range is 57-71C (135-160F) because few thermophilic organisms actively carry on decomposition above 71C (160F), it is undesirable to have temperatures above this for extended periods.
Thanks Angelo. I turned the compost again today and add 7kg of sawdust to add more carbon. It did smell slightly of ammonia, but the fireblight fungi that i saw yesterday was gone. I probed a few more places but it was only the top center at 71 deg C, the rest of the compost was around 67 deg C. Hopefully the sawdust corrects the ammonia.
That’s great news, sounds like its working! 🙂
Great tips! Thanks for sharing!
I really like this simple composting system. im trying my best to do in your simple explained way . Thank you ?
You’re welcome! 🙂 From the many comments on this article, you can see it works fairly well, in all different seasons, all around the world. Let us know how it goes!
Awesome . I am following it
Hi I see from your link to the article on what to compost and what not to compost, there is a clear recommendation NOT to compost citrus peelings and onions. The rationale given is that they kill worms.
I have read elsewhere that both are fine to go in, but also others say that only put them in in moderation. So the obvious question is how much is ok?
We have an orange or two per day go in. I always cut the peel up into small chunks, (quarter to half inch sq), and perhaps 5 onion peelings a week for about 8lb of composting materials per week, plus more from the allotment in summer and autumn season (potato leaves, bean leaf etc etc)
Overall, I find a good load of red worms in my compost so perhaps I have answered my own question. I have been following the hot composting method for about 7 years. Some comments:
* I use a bin (two actually, one to fill, one to let process) * I cut all material into the smallest size that is practical * Mid Wales climate by the sea, never too hot or too cold ambient temps (range – 2C winter’s night to +30 C summer’s day) cools the bins off in winter and helps heat in summer, but the temperatures I usually see are 5-10C max in winter, 30-37C in summer. * appropriate good mix of C:N maintained, I think! * Height of each bin is about 3ft 6in. Diameter about 2ft, so much small than your recommended size * Bin contents are turned using a fork every 2-3 weeks * Result is I never get anywhere near high enough temperatures as suggested for the Berkeley Method, and as a result the compost arrives ready for use in 26 weeks not 18 days!! * But it is good compost, so thanks or the suggestions. I am certain that it is better compost than I would ever have managed without your recommendations.
Oh, two final queries:
1. I have also read that office / photocopy paper is not good even if shredded. What do you think? 2. Do you know why red worms come to the top of the bins and try to escape (some do get under the lid!), as the compost is close to being done, ie when the green materials have all gone and it is turning closer to brown mush but not yet crumbly / dry?
Many thanks
Jonah
________________________________
Hi Jonah,
Thanks for your comment!
The oils from citrus peels and exudates from onion (Allium) family roots are irritant to earthworms and compost worms and repel them. They’re irritant to us too, as anyone who has ever sliced onions or accidentally got a fine spray of citrus oil in their eyes when peeling citrus. That’s why they aren’t meant to be put into worm farms. These compounds are also anti-bacterial, and composting depends on microbes to break down plant materials.
Loading a compost pile with citrus peel and onion family scraps will slow down the composting process, and if enough is put in relative to the other materials, it can temporarily stop it until the materials start to break down, as there are specific organisms which can break them down, and they will break down eventually. I’ve placed a whole layer 15 cm (6″) thick of citrus over a full compost bin after I had to remove a lemon tree loaded with unripe fruit whose roots had rotted out. The lemons sat there for many weeks before they started to be broken down by what I suspect to be fungi and molds. After that they broke down into the compost.
Putting an orange or two per day and 5 onion peelings a week into 8lb of composting materials a week is perfectly safe, and will not adversely affect the composting process. The fact that you have earthworms in your compost means that you’re doing it right, because they only move into completed compost, and that means your compost is working! Well done! 🙂
To answer your last two questions:
Office and photocopy paper is not good even if shredded, it’s toxic and contains some nasty chemicals – Why You Shouldnt Use Bleached or Glossy Paper in Your Compost or Worm Farm
Earthworms climb up to the lid of compost bins when its going to rain or something bad has been put into the compost – Gardening Questions #006 Why Do Earthworms Gather at the Top of Compost Bins or Worm Farms and Try to Escape?
Thank you so much for taking time to do this detail information how to make the hot compost.
Much appreciated your explanation, this has explained many of the problems I have being facing.
Now I can put them right using your knowledge.
God bless
Could you clarify…..It says on day 5 to leave it for 4 days and then below it says to turn it on day 6 and 8?
Sorry – confused. Thanks so much!
Thanks for pointing this out, I need to make this a bit clearer and update the information!
As the summary earlier on explains, with the 18-day Berkley method, the procedure is quite straightforward and consists of three basic steps:
1. Build compost heap
2. 4 days no turning
3. Then turn every 2nd day for 14 days
With 4 days not turned, and terning every second day over the next 14 days, 18 days will have elapsed and you’ll have perfectly made hot compost! 🙂
Thank you for this, very well explained =) I would like to ask something since I’m about to do something I might regret so hope you can advise me just before that happen! I just finish composting a pile of grass clippings and my idea was to use it alone to fill my garden beds and start transplanting right away. Will it burn the plants this way?.. The temperature is now low and its all black and crumbly…
Many gardeners mix up manures and compost when thinking about precautions needed before planting a garden bed.
Completed compost is safe to plant straight into, there should be no concerns there at all. When you see earthworms in compost, it means it’s broken down and cooled down, and safe for them to move into, and safe for seedlings to grow in.
Really strong manures such as chicken manure and horse manure should be dug into the soil and left for around a week or two, then planted. They can contain high levels of salts, and can also heat up while in the ground due to high nitrogen levels, which may burn delicate seedling roots. All manures should be composted first before being used in the garden, as these problems are exacerbated with fresh manures, salt levels are even higher, and they can heat up to the point of steam rising!
Dear Angelo,
Thank you so much for the time you took to answer my question. I followed your advice and transplanted my tomatoes, luffa, indigo and others plants directly into the finished compost. So far so go, 3 days have passed and they loock very healty with barely any sign of transplantation shock or something. Thank you once again for your time and advices.
Best regards, Raquel
Thanks Raquel, that’s great news, thanks for sharing how it all went well! 🙂
Great explanation.
Wondering… we eat quite some fish, I’ve never tried composting it and want to know, if you turn the pile where do you put the fish? On the outside too? Or do you “fish” it out and put it back in the middle?
Hi Saskia, some people in rural areas even look for road kill to add to their hot compost pile. Where does it go? Right in the middle, the very core of the compost pile where it’s the hottest. After the compost pile is constructed, it needs to sit for four days before it is turned. By that time, the materials in the very centre will be totally broken down, with just clean bones left.
Unless you only eat fish every 18 days, and create a huge 1.5m tall compost pile that often also, your fish scraps might pile up! A good way to process the fish waste is with a bokashi bin – see my article – Bokashi Composting, How to Process Waste that Cant Go in Your Compost or Worm Farm
Hope this helps! 🙂
Hi,
Sorry if this is a question that has already been answered but the posts are many so I have scrolled through quite a lot and am not sure if I have found the correct answer to my question which is:
I have goats and their straw bedding is also mixed in with their droppings and their urine. Would this be carbon based or Nitrogen based? I just need to know so I can start my hot compost. I have an area 4ft by 4ft made using pallets so need to know how much of this soiled bedding I should use compared to green (nitrogen) and brown (carbon) based ingredients? The bedding is made up of straw and dry grass so not green but half of it is wet with poop and pee which is why I am cleaning it out!
Thank you
Hi Debbie, excellent question! The goat manure and urine is a high nitrogen source, while the straw bedding is a high carbon source. Together the two create a fairly balanced mix which can be composted without any additional nitrogen or carbon materials. If you’re adding any other materials into the compost, then you would add either nitrogen or carbon to balance them, but if you’re adding green plant prunings, clippings, weeds and garden waste, they’re fairly balanced with a C:N ratio of 25-30:1 which is the ideal we’re aiming for.
Many thanks for your speedy answer, I thought this would be the case, but wanted to be sure.
Your article is by far the best I have read on composting and although it was a number of years back, I an glad you still found the time to answer – Much appreciated 🙂
No problem Debbie, you’re welcome! All the articles on this website are active, even if they were written a while back, and we answer all question! 🙂
Hi, I was doing so well with my first hot composting, am on day 10 and went to turn the pile and it has gone horribly smelly, rotten and cold. We have had torrential rain for the last couple of days and the compost is completely sodden, any suggestions as to what I should add to get it going again. It has finally stopped raining!!
Thanks for the best info i have found on the web for composting! I have tried it and its working although on day 13 my temps have dropped after the last turn and now although slowly rising again are down to 35c. Question i hope can still be answered after this post has been going so long (it took me a whole 3 hours of reading every reply!)
1) I am able to get a lot of farm veg waste and the last few times I have been blending it up to get the particle size as small as possible which i also used to do when cold composting …is there any downside of blending the items – I don’t mind the effort as long as its of benefit and is not making the particle size too small. I blend with small amount of water so it breaks up easily.
2) I have been using urine on my compost heaps and save my wee and every week pour this onto the cold compost heaps and now intending to do on my hot one. Is there a point when too much urine is detrimental?
Please keep these posts coming as very interested to hear others thanks
Andrew
One of the best and comprehensive article on berkeley hot composting, i am bookmarking it so i can read it again.thank you , you really inspired me to learn more.
Thanks, you’re welcome! 🙂
Hi Angelo
Thank you for you fabulous article. I have read through all the comments and replies and it has been very informative. What are your thoughts on using dry eucalyptus leaves as the carbon content? The other brown content I have is an endless supply of is pine needles. If I build my hot compost using eucalyptus plus pine needles and then various nitrogen matter, will this be ok?
Also, I can access seaweed that washes up on the waterfront of a lake (saltwater). It appears dried as it looks and feels different to that still growing in the water. Is this carbon or nitrogen?
Thanks so much.
Hi Kristy, thanks for your kind comments, you’re welcome! 🙂
You can compost pine needles, they make the compost a bit more acidic though, which is why they’re great to mulch blueberries with.
I wouldn’t compost eucalyptus leaves, many gum trees release chemicals which stop other plants growing, see my article – Can Eucalyptus Leaves be Composted or Used as Garden Mulch?
If the seaweed is brown, it’s a source of carbon (with a lot of trace elements), and it would be best to wash it to remove any salt from the surface.
I found a simple compost calculator that’s based on volume. https://urbanwormcompany.com/composting-calculator-carbon-nitrogen-ratio/
I was wondering about my leafmould pile that’s part done e.g. compacted and wet broken down leaves. I have been using the leafmould and horse manure and leafmould and kitchen waste based on the 1 green to 2 brown by volume and it has been working fine.
Leafmould is a denser material than dry leaves however the ratio seems to work fine. I guess there is a lot of latitude !
Hi Charles, there is quite a bit of latitude in getting the right carbon to nitrogen ratio, remember we’re just copying what nature does on the forest floor, but optimising the ratios of carbon and nitrogen rich materials to speed up the process.
Thank you very much for the article
Great explanation.
miss.
1. if we can give extra heat for this hot method can we make compost quickly .
2 can we use a cylinder do this hot composting.(cylinder size diameter 60 cm and hight 90 cm )
3. I want to know how to make compost in 24 hours.
Great article! I do have a question regarding having enough garden waste to compost using this technique. In my garden I manage to have enough nitrogen rich and carbon rich waste to build a big enough pile, however, it takes me one to two weeks to gather everything up. Is it possible to start building the pile gradually this way or is it better to construct it all in one day, as you have instructed? If the latter, how long can I keep the nitrogen rich garden waste in a separate container so that it can still be used for building a hot composting pile?
my question is, in short, will hot piling only work if the green waste is freshly cut? (i.e. on the day)
The longer that green waste is left lying around, the more of its nitrogen content that is lost, so it’s best to compost it as soon as is practical.
Rute, there is a further reason to use the green material when its fresh, particularly if your green source is fresh cut grass. Leaving the greens on it their own will also create a clumpy wet STINKY mess. It is the only thing that I have found creates such a nuisance in my compost area. If you have an active pile with enough browns, using the fresh cut green grass as it becomes available will almost always help spike the temperature, provided your ratios are within range.
A really helpful and well explained article. Thanks.
I think many readers may be discouraged by excessively complex or arcane lists of ingredients. I have been making several cubic yards of hot compost annually for 35 years with fallen leaves and mowed grass clippings mixed at a three to one ratio respectively. The only catch is having to collect fall leaves and store them until the grass starts growing again (I store mown leaves in 50 gallon plastic leaf bags). I also add mown garden vegetation and kitchen vegatative waste, but they are relatively insignificant additions to the leaf/grass mix.
The more ingredients the better the quality of the compost, but a simple two-ingredient compost is much better than no compost, so thanks for the great suggestion, much appreciated!
A simple way to store fallen leaves is to make a leaf litter cage – simply mark a square area on the ground, and then drive four timber stakes in the ground at each corner, then wrap some wire mesh, such as chicken wire around to create a bin. Tie the ends together with some wire around one of the stakes. Since many types of deciduous tree leaves break down very slowly on their own, the leaves can be left there for months, and can used for composting as needed.
Hi,
Can I compost just hay (or majority) as it is the right C:N ratio?
Thanks
Yes, hay will compost well on its own, but it might not start heating up without some high nitrogen materials added in the centre of the pile, and if it does work, it will only yield a very low quality compost that has exactly the same nutrients in it as the hay did originally. The carbon in straw-like materials is classed as labile carbon, it goes into the soil quickly, and leaves fairly quickly, unlike the carbon in woody materials. There’s not much to be gained composting straight hay. Simply mulching the garden beds with the hay will yield similar results, for much less work.
Thanks for the quick response. The original idea was to have it as mulch but unfortunately the pea hay I bought was littered with seeds, so unfortunately mulching isnt an option. Now Im stuck with bales of hay that Im trying to compost quickly to use, unfortunately I dont have a lot of nitrogen rich ingredients to add and my current compost bin is slow due to being mostly carbon rich. Help 🙁
Hi Tom, they say permaculture is imagination and information intensive, but not resource and energy intensive. Time to get creative! A small amount of blood & bone fertiliser, which is very high in nitrogen, will heat up a compost pile very quickly! So will comfrey or nettle leaves, and these grow on their own. If we look at the list of C:N ratios for composting materials, you’ll notice that the material with the highest nitrogen content is urine, with a C:N ratio of 1:1, but keep off the salty food when using this resource, if you get my drift…
Hi. I hope you can provide me with some advice please. I started my hot compost pile with various brown matter (leaves, pine needles and seaweed) and green weeds, coffee grounds and urine. I used the 2:1 volume ratio. On Day 5 I turned but the pile was cold. I added more green waste (grass clippings and garden waste, as I realised that weeds were not high enough in nitrogen to use the 2:1 ratio, and started at Day 1 again. The pile is at least 1.5 X1 x1m.
I turned on Day 5 and was excited to find the pile was 55 degrees at the core. Today is day 7 and I turned again today but the whole pile is cold. I am not sure where I am going wrong. I added half a bag of cow manure today ( it was all I had with lockdown) as I turned and a little more water. What should I do next?
Also, if the pile is not hot on taking a temp reading before turning, can I leave it a few more days or is it best to turn anyway?
Thanks so much. I am determined to get this happening!
Also, are shredded free Camphor Laurel leaves suitable as a nitrogen source?
So Im 60 hrs past the time I pulled the hose out of the pile after soaking. My pile is at 162 right now. Should I turn it now or should I let sit for another day? Id like to add this article has been a game changer for me. You really break it down to where I can retain the info. One of my biggest problems. This is my second pile Ive started. The first one went good. Definitely went longer then 18 days. This time I used material I think will break down faster and also purchased a leaf shredder.
Thanks Chris, great to hear the first hot compost pile worked well!
It’s important to turn the compost on the prescribed days, as that increases aeration of the compost and keeps oxygen levels high, which keeps the compost hot, and also feeds new material from the outside of the pile into the hot core where the compost bacteria do their work.
The compost can take a bit longer than 18 days if the materials are not broken up as much and the weather is cooler. Breaking up the compost materials into smaller pieces really speeds the process up drastically, it gives the bacteria moire surface areas to act on. It’s amazing how much faster mulched woody material and shredded leaves break down.
Question on cold composting.
I can understand any type of compost pile becoming anaerobic if too many green materials are added in comparison to brown, it’s then kept continually saturated with water, it’s not turned, or it’s in a covered pit, trench, or container.
My question is, why would you state that “cold” composting happens in an anaerobic environment? How could a open pile become anaerobic pending one is not allowing the basic issues noted above to occur?
Oxygen surrounds and infiltrates the compost material just as easily as oxygen permeates into a soil as moisture recedes after a rain or watering. In neither scenario is oxygen completely excluded for long periods to create an anaerobic environment.
Composting is just managed decomposition, and the vast majority of decomposition in the world never gets to the “hot” thermophilic stage and beyond. It just stays in the earlier mesophilic stage where temps stay relatively low and materials take long periods to break down. These bacteria are not anaerobic in an open pile as noted above or out in nature when oxygen isn’t sealed out. One can easily “cold” compost without allowing the pile to become anearobic.
Hi Mark, thanks for your question. I explain a lot of what you’re asking in my article – What Happens If You Dont Turn Your Compost?
The reason we turn compost is to aerate it, and add the materials from the outside of the compost pile to the inside where it’s warmest and the greatest amount of composting microbe activity takes place.
Air, and therefore oxygen, won’t permeate into a compost pile very well on its own. As the organic matter breaks down, the particles become smaller, and more closely packed together, and just from the breakdown process alone they also release water, creating a wet mix of decomposing vegetable plant matter, which excludes air quite well, and has no air spaces for air to enter. Soil is comprised of around 45% mineral content, with a maximum of around 5%, organic matter, and the mineral particles of sand, silt and clay create various degrees of porosity. Compost is 100% organic matter and turns into anaerobic mud when wet.
Additionally, the vacuum created by rain falling on soil with good porosity which drags air containing oxygen to the roots of plants is a soil phenomenon. Many climates don’t have much rain, mine included, and too much rain will make a compost pile too wet, and stop the process, so people cover their hot compost piles with a plastic tarpaulin sheet (tarp) in cold, wet climates. Many people cold compost in compost bins, which have lids to keep the rain out.
Of course its definitely possible to make cold compost without it becoming anaerobic, and the way to do it is to turn the compost with some kind of tool, or using a compost tumbler bin, which aerates the compost and keeps the composting process aerobic! 🙂
unlike soil, which is composed of minerals which can create air spaces. Once the compost/soil bacteria have used up the supply of oxygen in the centre of the pile .
It just seems like in either hot or cold composting, as long as people don’t overdo adding in green plant material and keep the pile continually saturated, that anaerobic conditions are easily avoided.
For hot composting you are managing decomposition it to a higher degree. So this means that you are ensuring that the moisture content is consistent, the mixture content between brown and green material is consistent, the airflow is consistent, and the volume is optimized to retain heat. This all provides the optimal environment for the different phases of composting.
With cold composting since the environment isn’t managed to these optimal levels, the pile may be allowed to dry out to some degree, the levels of green materials may be allowed to run low, the level of airflow is reduced as materials break down but that does not mean it’s completely lacking oxygen, the pile may not be started or kept at the optimal volume. All of these allowances only slow the decomposition process but do not mean the pile is running in an anaerobic state and producing hydrogen sulfide and other smelly gasses.
I suppose in the end, the addition of too many green materials and/or keeping the pile saturated is the cause of anaerobic conditions but cold composting by itself is not equivalent to anaerobic composting.
Hi Mark, you almost nailed it perfectly in your first sentence – “It just seems like in either hot or cold composting, as long as people dont overdo adding in green plant material and keep the pile continually saturated, [and aerated] that anaerobic conditions are easily avoided.”
Cold composting is a slower and less productive version of hot composting, and works great as long as it’s done properly. A good cold compost doesn’t go anaerobic, that only happens when materials break down and collapse in on themselves, excluding air. Remember that a cold compost pile breaks down to 20% of its original volume, so it can collapse a lot!
You’re 100% correct, cold composting is definitely NOT anaerobic composting, and never should be. On the other hand, bokashi composting of food waste is an excellent anaerobic composting fermentation process that is carried out in an airtight container to break down all manner of food scraps, even things that should never go into compost.
I still say if it collapses on it self at the end when things are decomposed, as long as it’s not overly saturated, it won’t run anaerobic. This is what would happen in nature with all sorts of decomposition.
Bokaski, I thought you still had to let it “compost” after you are done fermenting it? That seems like a lot of work to me!
The reason we aerate compost and get the mix of carbon to nitrogen right is to speed up the natural process. It takes over a hundred years or more, depending on climate, for nature to build an inch of soil. The rational of composting is to do what nature does, but faster!
To convert bokashi bin contents into fertiliser takes an extra step, but once they’re finished fermenting or pickling they’re ready to bury in the soil. Finished bokashi is fantastic for anaerobic compost piles, as the microorganisms function well in that environment. Just make a big hole in the middle of the compost pile, pour the finished bokashi contents in, cover it well, and don’t disturb it. The anaerobic microorganisms will work to break down the compost materials within the pile, and will continue to do until oxygen reaches the centre of the pile, or they finish their work, whichever comes first.
Hope this helps! 🙂
Wow! Still the best explanation on the web after 11 years! Thanks so much
You’re welcome! 🙂
Very useful information! Thank you.
I have one question: is there any risk that the compost heap get so hot that it gets on fire?
Compost piles require a certain level of moisture to break down, they get hot but not too hot to catch fire. They’re not like large haystacks where lots of dry, combustible material heats up from a damp core and ignite the abundance of very dry material around it.
Angelo,
This is a wonderful website, which has inspired me a great deal here on the other side of our warming planet – In Bend Oregon USA. Particularly these instructions on hot composting are spot on, and unfortunately there are a lot of guides out there on the internet that only intimidate or mis-guide people, turning them away from something very helpful to both our gardens and the environment, and also our wallets.
I retired in Jan of this year, and over 9 months have been working to convert my generous suburban backyard into a working organic vegetable mini-farm. My #1 goal was to generate my own soil with a minimum of purchased items – I think I have demonstrated I can do so in just one summer, time will tell.
My first step (mini-blunder?) was to purchase a medium size black plastic tumbler/composter. I now realize this isnt much of a composter, however it is a decent pre-composter for all of the kitchen scraps. I fill it 2/3 with dry brown material and them continuously add my kitchen scraps in between pile builds. This is a useful tip for anyone that doesnt want to attract rodents, and mine is odor and nuisance free. I simply dump it when I build my piles and start over again. I hope it will be especially useful to get me through the winter.
I have now built 5 large (perhaps 1.5 – 2 x the size you describe) hot piles over the course of a long summer. I had loosely followed the instructions of others, and through trial and error discovered that your description is actually what has worked the best for me. I have now also come up with a soil recipe which I cannot wait to see how it works out (my compost, sphagnum peat moss, coco, perlite, recycled soil are the mains). I have been able to make enough compost for finished soil of 4-5 cubic yards, and the purchased materials cost me ca $100.
I did make one more investment that set me back about $450, in a med size chipper/shredder. You just mentioned this in passing, for me it turned out to be a game changer. Where I am, there is no shortage of greens (lots of fresh grass clippings) but browns are less abundant. I needed something that would chop up tall, dry desert grasses, pine needles, and especially pine cones. The chipper does this very well, solving my brown material problem. It also illustrates that surface area is a key variable, one will produce a better compost more quickly if you chop things down to smaller size.
Sorry to be so long-winded, I just wish I found your site earlier, would have saved me some headaches. I am trying to expand my thinking and efforts beyond composting as we speak. To any beginners who made it this far: try this method as described, and realize you will have to improvise a bit to use whats around you. You will be rewarded handsomely!
Thanks, Ed
Thanks Ed, really appreciate you sharing your experience. A chipper or mulcher makes a huge difference when using dry, carbon rich or woody composting materials, breaking them up speeds up the process remarkably!
Angelo,
Back again near the end of a productive winter. I added a 12’ x 12’ greenhouse in Nov and have yielded a wonderful variety of winter veggies. On the edge of my seat to see what I can do outdoors this summer.
I wanted your views on tips for ‘re-habbing’ a winter pile. I have successfully heated it up, but I am uneasy about whether it will be cooked enough to avoid weed seeds (my biggest headache from my initial piles). Description: my pile is large, about 6’ x 6’x 6’, about 60% is the largely finished last pile from the fall. It looked pretty good, but unavoidably did not stay hot enough to be considered finished in my book. So it sat for the winter cold. About a week ago, I re-started it with my blend of a full winter’s partially composted kitchen scraps, which were stored in a tumbler with a blend of browns, and I got a nice source of finely chopped fresh lawn clippings. As a reminder, my browns are a mix of desert grasses, pine needles and shredded pine cones. As it is still cold here, I have been covering the pile with a thick plastic tarp.
I got the pile heated up nicely and it hit 150 deg F in about 48 hours, then after the first turn on day 4 it has just reached 130 in the core, and around 100 on the surrounding edges about 10” in. It is visually progressing well, and already most of the vegetable matter is digested. My primary concerns are 1) can I keep it hot enough for long enough to ensure the weed seeds are toast; and 2) do I ultimately have too much compost from the fall blended in to be able to sustain high temps to succeed.
Ideas? Tips? Thanks, Ed
PS. My #1 learning is that my final pile the fall will be planned and timed to ensure it is 100% finished, so I don’t have this worry and have usable material to start the spring. This way everything I collect over the winter can be used to start the first spring pile properly, and so on.
Hi Ed, if you’re reusing material from the previous compost pile, you’ll need to add more nitrogen-rich materials to get it to heat up again, and break it down even more. So, don’t add too much carbon-containing materials, but add plenty more green garden waste and manure. Please let us know how it goes!
Angelo,
Thank you for providing such gem content through this website,
I have been following this website for some time and it has helped me understand more about global warming and other aspects of environment. And I have been following your tips on managing my garden and kitchen waste.
Can I just sprinkle compost on top of established beds & NOT dig it in, we have sandy gutless soil in Perth WA
Hi Jo, if you want to sprinkle compost on top of garden beds, and not dig it in, you have cover it with mulch, that’s what I do in my no-dig gardening.
If compost is left exposed, the sun will dry it out and the sun’s UV will sterilise it, killing all the beneficial bacteria. The valuable humus will needs to be kept moist and covered work , and fertiliser or compost left on the soil surface will lose the valuable nutrient nitrogen to the atmosphere. Throwing compost on the soil surface uncovered is a real waste, as it just becomes a very bad mulch. If we look at how nature adds compost to soil, it’s always composting underneath layers of leaves on the forest floor, and more are added to protect what’s underneath as the lowest layers become compost.