The Complete Guide to Worm Farming, Vermicomposting Made Easy

close up of compost worms in worm farm

Worm Farms are a great way to recycle kitchen waste and food scraps into one of the best garden fertilizers available!

It’s very easy to maintain a worm farm, it takes very little time and effort, and you can set up worm farms in the smallest of spaces, such as balconies and courtyards.

Worms farms are in fact worm composting systems, or more correctly, vermicomposting systems, and earthworms are one of the fastest composters there are.

In this article we’ll discuss how worm farms work, how to set up a worm farm and how to take care of it.

Choosing a Worm Farm

You can buy or build a worm farm, and they come in all shapes and sizes to suit all tastes and requirements.

Most worm farms consist of a set of stacked trays with legs, and don’t take up much room at all. They are ideal in size for a small household.

If you’re after a larger capacity worm farming system, one that can process large amounts of food waste, you can make one out of a recycled old bathtub or buy one of the commercial wheelie bin worm farms. These larger worm farms are ideal for places that generate lots of food scraps, such as larger families, schools, cafes, restaurants or workplaces in general.

It’s important to choose a worm farm that will fit in your available space that can cope with the volume of food waste you produce.

worm farms and compost bin
My three worm farms on the right, next to one of my compost bins.

It’s important factor to consider the ‘footprint’ – how much space the worm farm takes up on the ground. As you can see in the picture above, my three worm farms occupy a fair bit of space, luckily it’s in an unused corner of the backyard. I started with one worm farm , then added one more to cope with extra kitchen scraps, and then was given one – it wasn’t planned to run three side-by side!

A bathtub worm farm has a capacity of around 200L, and as you’d expect, it occupies the same space as a bathtub, which is a fair bit of space!

A wheelie-bin worm farm can have a capacity of 140L, 240L or 360L and occupies very little space on the ground. It and has the advantage of being moveable because in has wheels. Consider your requirements when purchasing, and you’ll be well rewarded, as worm farms last a very long time and are a great investment for the organic gardener!

wheelie bin worm farm
An innovative wheelie-bin worm farm that provides high capacity and occupies very little space, can be purchased complete or as a retro-fit kit to convert existing an existing wheelie bin. (Photo credit: Worms Down Under, , photo used with permission)

How Does a Worm Farm Work?

Worm farms use earthworms to break down organic matter, such as food scraps, to produce worm castings and the liquid ‘worm wee’, properly termed worm casting leachate.

Kitchen scraps in a worm farm break down very quickly, this is the ‘before’ photo, with a mix of fresh scraps, and others in various degrees of breakdown.

worm farm with kitchen scraps
In an established worm farm, kitchen scraps disappear in a few days

Here’s the ‘after photo’, when the process is completed, all that remains are worm castings. The kitchen scraps are completely broken down, and are now unrecognisable.

worm castings and worms in a worm farm
The magic of Nature, kitchen scraps become nutrient-rich worm castings!

All types of earthworms can do the same work, converting organic matter into valuable worm castings, but some breeds do a better job than others, so naturally, we choose the best worms for the job!

The earthworms used in worm farms are in fact compost worms, which are different to the regular earthworms found in garden soil. Compost worm are surface feeders and don’t burrow deep into the soil like garden earthworms do. The various breeds of compost worms, such as Tigers, Reds and Blues, are capable of eating their own body weight in food each day, so a kilogram of worms will consume that much food daily! By comparison garden earthworms only eat around half their body weight each day, so they aren’t as good at composting lots of material really quickly, as it takes them twice as long.

It’s important to keep in mind that compost worms won’t survive in your garden soil. Being surface feeders, they can’t burrow deeply into the ground to the cooler soil in the heat of summer like regular earthworms, so they don’t survive for long. They also need thick layers of composting organic material on top of the soil to feed on, so if there’s no organic matter over your soil that is breaking down, they won’t have any food.

All earthworms are part of an ecological class of organisms called decomposers, they eat rotting organic material and turn it into worm castings. Since they don’t have any teeth, earthworms need to wait till their food start to break down before they can begin to eat it. If their food is chopped up or broken up, it breaks down faster, and the worms can eat it sooner.

Now that we’ve covered basic earthworm theory we can now look at worm farm designs.

diagram worm farm design

Worm farms are usually made from two stacked trays:

  • The top tray contains the worms and food scraps.
    • It has a lid to keep pests out, with air holes in the lid so the worms can breathe.
    • It has drain holes in the bottom which allow any liquid to drip out.
  • The bottom tray collects the liquid that drips out of the top tray.
    • It has a tap or outlet on one side where the liquid can be collected.

The liner that sits at the bottom of the top tray stops the worms from falling through the drain holes into the liquid below and drowning. In commercial worm farms a piece of cardboard or some newspaper works fine as a liner. In homemade worm farms, where the drain holes are bigger, use a piece of shade-cloth or window screening first, then put the cardboard or newspaper down over it.

The worm bedding is where the worms live, it is usually just a damp layer of coconut coir, but you can use other materials such as damp shredded newspaper, or well-aged compost or manure.

The food scraps are kitchen scraps and other materials that the worms can eat – we’ll go into detail of what you can and can’t feed your worm later on in this article.

The cover which is also called a ‘worm blanket’ is an old hessian sack or a whole newspaper, it helps create a dark, cool and moist habitat by providing a cover over the bedding and their food, which encourages them to move into the food and eat it. The cover will eventually break down after a few weeks as it is biodegradable.

This is the basic worm farm design, but there are some variations. Many worm farm that you buy will have two or more top trays, the idea being that when the top tray fills up with worm castings, you can just add another tray to the top of it, and start putting kitchen scraps in the upper tray, and the worms will move up to the food. That also lets you remove the lower tray of completed castings to use in the garden while the worms are busy eating in the new tray.

Lets have a look at another worm farm design and see how it also works.

How to Build a Bath Tub Worm Farm

Large scale worms farms made from recycled bath tubs don’t have multiple trays, just a single level.

The bathtub is supported off the ground on bricks or it sits in a wooden stand or frame, and a bucket is placed below the drain hole to collect the liquid. The drain hole is covered with mesh or screen so only the liquid comes out.

The bottom of the bathtub is filled with coarse gravel for drainage, then the bath is lined with shade cloth above the gravel and then filled with bedding material. The rest of the layers are just like any other worm farm.

Since bathtubs don’t come with lids, a timber sheet or wooden cover is used to protect the worms and keep them shaded.

home made bath tub worm farm design
Home made bath tub worm farm design
DIY bath tub worm farm
Worm farm made from recycled bathtub sitting on tubular steel frame from recycled dog bed!

How to Set Up a Worm Farm

When setting up a worm farm it is important to choose the right location. Worms like a cool environment, so if you locate the worm farm in a shady spot outdoors where it will not overheat from exposure to direct sun, your worms will be happy.

You can place the worm farm on a shady side of a fence, at the side of the house where there isn’t much sun, under a tree, or even inside a shed or garage as long as it doesn’t get really hot in there during the summer. A protected spot on a balcony will work just fine too.

It’s also important to set up the worm farm in a location where you can easily get to it, so it’s ideal to locate it close to your kitchen, which will be the source of kitchen scraps for your worm farm. If you can’t easily access your worm farm you’re less likely to use it.

diagram permaculture closed loop recycling system
The Permaculture design principle of Relative Location explains how to set up a closed-loop sustainable gardening system with a worm farm and kitchen garden

TIP: Keep a small bucket or container with a lid in the kitchen to throw your food scraps into, and empty it into the worm farm when you’re done. Lining with a piece of newspaper helps keep the container clean and the newspaper will be broken down in the worm farm with the food scraps.

kitchen scraps bucket for compost and worm farm

To set up the worm farm, it’s quite simple, especially if it’s one you purchase, as they all come with instructions which are similar to those you’ll find below.

diagram worm farm setup

Here are the seven basic steps to getting a worm farm stated:

  1. Assemble purchased worm farm or construct one yourself (see instructions for building a worm farm here).
  2. Place the liner (about 0.5cm (1/4”) of newspaper or a sheet cardboard) in the top tray.
  3. Prepare bedding material (by either soaking coconut coir or shredded newspaper in a bucket of water till it is damp, or acquiring a container of well-aged compost or manure) and put into the top tray above the liner.
  4. Place the cover (worm blanket) made out of a whole damp newspaper or a damp hessian sack over bedding.
  5. Add worms onto the bedding under the worm blanket cover, begin with around 500-1,000 worms.
  6. Allow a few days for the worms to adjust to their new environment.
  7. After a few days, begin to feed the worms lightly.

What to Feed Your Worms

Firstly, what you feed your worms is important. There are some things that worms won’t eat, and there are other things that are just simply unhygienic to put into a worm farm.

Remember that a worm farm is a vermicomposting system, it is used mainly for food scraps, which break down very quickly. Woody garden prunings and green waste are slow to break down and are better placed in a regular compost bin instead.

Let’s have a look at what you can and can’t put in your worm farm:

Things You Can Put In Your Worm Farm

  • Fruit & vegie scraps
  • Bread & cheese
  • Cooked vegetables, grains, pasta & rice – basically all vegetarian foods, no meat-based sauces!
  • Coffee grounds & tea bags – as long as teabags are paper and not plastic mesh
  • Egg shells – great source of calcium, a mineral which worms require in their diet to stay healthy
  • Newspaper & unprinted cardboard (soaked) – no glossy printed pages

Things You Can Put In Your Worm Farm (With Caution!)

  • Vacuum cleaner dust – only if your carpets are natural fibre, not synthetic carpets!
  • Citrus & onions – only small amounts or none at all!
  • Pet waste – only in a dedicated worm farm for pet waste only

Things You Can’t Put In Your Worm Farm

  • Fish & meat – this will stink and attract vermin such as rats, use a Bokashi bin instead to compost meat
  • Garden waste – too slow to break down in a worm farm, put into compost bin instead
  • Glossy and bleached paper – this is toxic, you don’t want this anywhere near your garden
  • Fresh manures – many animals are treated for worms with vermicides, which pass into the fresh manure and will kill your worms, compost them first!

How to Feed Your Worms

Secondly, how you feed your worms is also very important.

Place the food on the bedding, beneath the cover, also known as the ‘worm blanket’, which is just a damp old hessian sack or a whole newspaper, fold it to fit if necessary.

When you first set up your worm farm, add a small amount of food, and as the worms begin to feed in a few days, then add more. Don’t overfeed your worms as the food will remain uneaten, and will begin to rot, which doesn’t create a healthy habitat for your worms.

When feeding the worms in the worm farm, don’t cover the whole surface with food, place the food to one side only, and try to cover half of one side at the most. Just in case the worms don’t like what you’ve just put in there, they can go to the other side of the worm farm where there’s no food. If you cover it completely they’ll have nowhere to escape to if they don’t react well to your latest food offering. Once that half covered with food is eaten, add more food to the other side, and alternate sides, so there’s always a food free side for them to move to if they need to.

diagram how to feed your worm farm

The worms in the worm farm will breed and the population of worms will grow. As they multiply they will eat food faster, and you’ll be able to add more food. The number of worm will eventually self-regulate to match the size of the worm farm and the food available, so after a while you’ll know how much food they can process.

How to Collect and Use Worm Farm Leachate

worm farm bucket collecting leachate worm wee
Worm casting leachate, aka ‘worm wee’, liquid gold for your garden!

Worm farms all have a tap or outlet to collect the liquid that seeps out from the worm farm, this liquid is often called ‘worm wee’ or ‘worm pee’ but the correct name is worm casting leachate.

To collect the leachate:

  • If your worm farm has a tap, just put a bucket under the tap, and turn the tap, the liquid will flow out to fill your bucket. When you’ve collected it all, close the tap, it’s that simple.
  • If your worm farm doesn’t have a tap, and just has an outlet (a pipe) for the liquid, then place a small bucket permanently under the outlet to collect the liquid as it’s produced.

Even if your worm farm has a tap, you can permanently leave the tap open and place a bucket under the tap, this will prevent flooding! This is how I prefer to do it, and in the picture above you can see how the liquid fills the bucket after a light rain.

To use the leachate, always dilute it with water first before you use it on your garden, as it may be too strong to use directly. Always dilute it 10:1 with water, that means one part leachate to ten parts of water. When it is diluted it will be the colour of weak tea.

It’s important to keep in mind that the leachate is it is not a fertilizer like worm castings, it’s more of a soil conditioner that improves the health of the soil as it’s full of minerals and beneficial microorganisms. Think of it more as a vitamin tonic for the plants and the soil, rather than a food. Since it’s rich in beneficial beneficial microorganisms, you should always dilute it with rainwater, because tap water is chlorinated and will kill all the good bacteria in there!

How to Collect and Use Worm Castings

The worm castings, or vermicompost, is ready to collect when the bedding material and the food in it has broken down well and all that remains is a dark, rich, fine, moist substance, in which you can no longer see the food scraps.

A good time to collect the castings is in spring and autumn, because this is a good time to fertilize your garden.

The trickiest part of collecting worm castings is separating the worms from the castings! You want to keep your worms in the worm farm. There are a few techniques for harvesting worm castings which allow you to separate the worms out which we will look at in detail below.

How to Separate Worms from Castings

1. The ‘Rainy Day’ Technique

If you have a worm farm which uses stacked trays, you can wait for a day when it looks like it is about to rain. On rainy days the barometric pressure in the atmosphere drops, and the worms sense this, so they rise to the top to avoid drowning when the rain comes down. This is a natural survival instinct that for when the rain floods their burrows and tunnels in the ground.

When they worms come to the top, they will all leave the lower tray, and will gather in the top tray or inside of the lid. When they all come up, you can quickly lift out the lower tray and put it aside for later use. Don’t leave it out in the rain though, as it will become overly waterlogged, and lots of beneficial bacteria will get washed out, put it undercover somewhere and use it in the garden as soon as possible after the rain has passed.

With worm farms that have a door at the bottom to harvest castings, simply harvest the castings and put them in a bucket for later use, but don’t leave them sitting in the bucket for an extended period of time, as there’s no drainage and any moisture at the bottom may become stagnant water.

2. The ‘Pyramid’ Technique

So what happens if it isn’t going to rain anytime soon and you need castings? Well, there are other habits that worms have which we can take advantage of – worms dislike light, so make sure you don’t expose them to direct sunlight when caring for them, they sunburn easily!

To separate the castings from the worms, gather your castings, which will contain worms, put on some rubber gloves, and place a pile of castings on a low flat container or board, and shape it into a pyramid shape. Do this in a shady spot outdoors.

The worms will not stay in the narrow pointed tip, and will burrow downwards to escape the light. Scoop off the tip of the worm casting pyramid, and put that into a bucket. Then reshape the pile into a pyramid with a new tip, and harvest the worm-free castings again. As you keep on doing this, the pyramid will get smaller and smaller, and the worms will keep moving to the bottom. When you have a small, low, flat pile full of worms, put it back in the worm farm.

3. The ‘Let The Worms Decide’ Technique

We can take advantage of yet another of the worms natural instincts to facilitate the harvesting of castings. When their bedding turns to castings, they will be basically living in their own waste, which is not their preferred environment. They have a preference for fresh bedding material with a supply of food.

If you push the castings to one side of the worm farm to make a space to lay down fresh bedding material, put fresh bedding in in that space, and only lay food on the fresh bedding side, the worms will move over to the area with fresh bedding and food, and will move away from the side which contains only their waste (castings) and no food. Once all the food is finished in the castings, they will decide to move out to the nicer side, and you can then collect the castings! This technique works well in long, wide worm farms such as bathtub worm farms.

In the process of harvesting worm castings, you’ll find earthworm eggs or cocoons. They’re easy to identify, they’re small amber or yellow eggs about 3mm (1/8”) in size which look like little beads but when you have a closer look at them they’re shaped like tiny lemons. Pick these out when you come across them and return them back into the worm farm.

Try to use the castings fairly soon after you’ve collected them, don’t let them sit around for a very long time, and don’t let them dry out, as they’ll lose their beneficial value.

Now that you’ve collected your castings, there are many ways that you can use them.

How to Use Worms Castings

  • In the garden – dig into the soil or place under mulch
  • Sowing seeds – add worm castings (up to 25% of total volume) to your seed raising medium
  • Indoor plants – add to the potting mix during growing season
  • Compost activator – add some worm castings to your compost bin to inoculate it with beneficial bacteria, which will help kick start your compost
  • Worm casting tea* – made similar to compost tea, full of nutrients and beneficial soil organisms, which can be used as a foliar spray on the leaves or watered into the soil.

Basically, you can use worm castings the same way you would use any slow-release organic fertilizer, it’s that simple!

* Note – How to make worm casting tea (or compost tea) is a process that would take a short article to describe so I haven’t included the instructions in this article!

Solving Common Worm Farm Problems

Worm farms are quite problem-free and easy to look after, but there are a few things to keep in mind that will make caring for your worm farm much easier. Here’s a few of the biggest problems you might face and some simple solutions.

Protecting Worm Farms from Rain

Unless your worm farms is undercover, it will get rained upon, and some rainwater will get in, depending on the design. This is a benefit in my mind as it flushes out the castings and makes a good supply of worm casting leachate (worm wee) that you can use in your garden.

If your worm farm has a tap, and the tap is closed, then your worm farm may get flooded!

The simple solution is to leave the tap permanently open and place a small bucket underneath as shown below. This will also prevent the tap getting blocked too.

worm farm with tap left open to prevent flooding
Leave the tap open with a bucket underneath to prevent flooding!

If you do need to leave the tap shut, you can save any worms from drowning if they fall into the liquid in the bottom by giving them and ‘island’ they can climb onto. Just place an upside-down terracotta pot into the bottom of the worm farm where the liquid collects. The terracotta pot is heavy enough so it won’t float and move around, and the surface is not slippery like plastic, which will allow the worms to climb the sloped sides as shown below.

diagram inverted terracotta pot worm farm island to save worms from drowning
Save your worms from drowning with an inverted terracotta pot ‘island’.

Also, remember to open the tap and collect the liquid from your worm farm once a week, and if your worm farm is exposed to the rain, collect the liquid immediately after it rains too.

Protecting Worm Farms from Hot Weather

The fastest way to lose all the worms in a worm farm at once is to accidentally let them get cooked in hot weather!

We’ve already discussed the location of the worm farm earlier in this article, it should be in a protected, shaded location away from direct sun. Sometimes, even the shadiest location might get direct sun exposure during summer, because the sun is directly overhead, or because the hot west afternoon sun comes in from the side as the sun lowers in the evening.

Worm farms can overheat simply due to the high temperature of a hot summer’s day, because the air outside is hot, and they’re in an enclosed container. To alleviate this problem, prop the lid the worm farm open a bit to let air circulate through and to release any hot air that may be building up under the lid. You can simply lie a stick across the top of the worm farm and place the lid over it so there’s a gap between the top edge of the worm farm and the lid.

On really hot days, you may need to cool down the worm farm by watering it with a watering can and rainwater. Make sure there’s some form of cover material (the ‘worm blanket’) in place such as newspaper over the bedding and food, to keep the worm’s environment dark and moist.

Open the tap to prevent flooding and place a bucket underneath to collect the liquid. Water with a watering can making sure you evenly dampen the whole surface. DO NOT use tap water if you can , it is contains chlorine, which will kill a lot of the beneficial bacteria on your worm farm! After wetting down the bedding and cover material, the water will slowly evaporate to create a form of evaporative cooling which will help the worms cool down.

The best way to protect worm farms from direct hot sun is to cover them with a screen of some sort that is light coloured and will reflect the sun, with sufficient air-space underneath it so it doesn’t trap the hot air over the worm farms and cause them to overheat. You can remove the screen in the cooler seasons, and put in in place during the warmer seasons.

I’ve found that cheap reflective plastic tarpaulin sheets, suspended high above the worm farms to allow air to flow underneath, work extremely well. You can tie the bottom of the tarp to a brick or other heavy object to stop it flapping around in the wind.

Pictured below are my worm farms (and a compost bin on the far left) sheltered behind a fence.

worm farms and compost bin
Worm farms in cooler seasons without cover
protecting worm farms from sun with tarp sheet

Worm farms kept cool in hot seasons with lids slightly open and reflective plastic tarp sheet cover

Dealing With Insects in the Worm Farm

It’s natural to have a few other insects in your worm farm, but some are unwelcome guests!

Ants do not belong on your worm farm, and it may be because it’s too dry in your worm farm, as ant’s don’t like moist environments.

To discourage ants, dampen down the worm farm with a watering can full of rainwater, and to stop them getting in there, create a barrier, an ‘ant moat’ by sitting the legs of your worm farm (if it has legs) in tray of water as pictured below.

worm farm with tap left open to prevent flooding

Worm farm legs sitting in plastic pot trays filled with water, forming a moat to keep ants out!

The water will evaporate on hot days so remember to keep it topped up. I’ve seen suggestions of using taller narrow containers filled with oil which won’t evaporate but in my mind that will create a disgusting mess as dirt gets blown in by the wind. I reckon water is a much tidier solution!

Smearing a band of Vaseline around the legs of a worm farm is another suggested solution but it’s likely to melt in hot climates.

Ants aren’t a problem unless you overload your worm farm with lots of sugary food, and if the food has been there long enough to attract ant’s there’s a chance you may putting in much more food than the worms can eat. Remember to chop up the food so breaks down faster!

Vinegar flies are those tiny flies that fly up into your face when you lift the lid on a compost bin or worm farm. They are attracted to rotting food, especially fruit, as are fruit flies, so the best way to prevent them breeding is to cover the food scraps beneath a damp newspaper (remember that all important ‘worm blanket’ cover over your bedding!)

Other insects such as millipedes are not a problem, they are decomposers and feed on rotting organic matter, returning the nutrients to the soil. Slaters, also known as wood lice, pillbugs, roly-polys or butcher boys are also beneficial decomposers and are in fact land-based crustaceans! Soldier fly larvae, which look like giant silver-grey maggots are also beneficial, though they look a bit creepy. Springtails are unmistakable little insects which hop around on the surface when you lift the lid, they are also beneficial, they’re all part of the decomposer community too, a natural part of the Earth ecosystems recycling processes.

If you see tiny white worms in your worm farm, they are not baby earthworms, these worms are entrachyadids, they are not harmful but do indicate that your worm farm has become a bit too acidic. Correct the acidity by sprinkling a small amount of garden lime, dolomite or wood ash (which are all alkaline) in your worm farm every few weeks.

Odour and How to Fix a Smelly Worm Farm

A healthy worm farm will have little to no smell, perhaps a faint but pleasant earthy smell just like healthy soil or a forest floor. If it has a sharp vinegar smell it may be too acidic, add crushed eggshells, garden lime, dolomite or wood ash to correct the problem.

If it smells quite offensive, it is an indicator that the system has become quite anaerobic from too much uneaten food. To fix this problem, stop adding any more food, add a sprinkling of garden lime, dolomite or wood ash, and lightly stir up the existing food scraps to aerate them on a regular basis. Once the smell disappears, then begin feeding the worms again.


As you can see, it’s quite straightforward to run a worm farm, it doesn’t take much effort to keep your worms happy.

Your worm farm will give you a free supply of valuable castings and leachate for your garden, which your plants will absolutely love!.

Time to get worm farming!

If you’d like to learn more about worm farming, please check out the following articles:

78 thoughts on “The Complete Guide to Worm Farming, Vermicomposting Made Easy

    1. Yes, they would definitely eat them! Dont overfeed them though, fish have very small stomachs and dont eat that much. Any uneaten food will rot at the bottom, which is a bad thing!

    2. My five inch goldfish will eat two or three one and a half inch worms each day until it gets fed up and will take a very much smaller sized caterpillar, the worms sink immediately so I have to get the fish’s attention before putting them in the water, caterpillars are difficult to sink so I don’t bother with them too much. Fish eat anything they can swallow, when I was a child we had a good fish for fifteen years in a small tank on a windowsill, for fun I would occasionally dig up a worm, hard work in our little stoney back yard, I don’t think it ever saw fish food, must have survived on February falling in the tank! More than once we came home to find a local cat had scooped it out, we tossed it back in and never gave it a second thought! Poor thing, occasionally we children would enthusiastically (misguidedly) try to introduce a companion, usually tiny cat fish or terrapins, it murdered all of them, most likely because it was a small tank with limited food supply.

  1. I have to keep part of my worm farm indoors in winter because it is too cold for them to survive where I live. I have plastics boxes indoors and I just empty half of them in my outdoor compost boxes in the spring and keep the rest to multiply the following year. I usually add a fine layer of sand in my bins to help the worms digest the food. Worms have a gizzard and the sand helps them grind their food to digest better.

    1. No need to move them inside, no need to really move them at all. My worm farms are permanently outside, just leave the tap open and put a bucket underneath so when it rains the worm farms don’t flood and you collect all the fresh worm casting liquid.

  2. For the suggested 500-1000 worms started with, approximately what quantity of leachate can be gotten in a week?
    Or can one sprinkle some amount of rain water on the blamket to ‘wash off’ the leachate into the lower bin for collection?
    Also in dry seasons, what water source can be used considering that there wont be rain water?

    1. It takes a few weeks for the worms to get established in their new home and start eating the food scraps.
      Yes you can sprinkle water slowly and gently using a watering can, like you do on a hot summer day to cool the worm farm, to get more leachate.
      When it rains, the rainwater flows through my worm farms, which is why I keep the taps open with buckets underneath, and I get around 4 litres of leachate from each worm farm after a heavy rain.
      If you don’t have rain water, use water that has been left to sit outside in a container open to the air for a few days as this may reduce the chlorine content in some cases.

  3. Thanks this has been the most informative page I’ve read on a long time. I have kept 2 worm farms for 4 years and have picked up many useful tips.

    1. You should be able to purchase compost worms from your local garden centre or from retail outlets that sell worm farms. In the unlikely event that you can’t source them you can use regular earthworms from your garden, but they’re only as half as efficient as compost worms as stated in the article.

  4. Hi! How do you prep the next tray you will add on top? I’m almost up to this on my current worm farm. The base was horse manure, shredded paper and food… do I repeat that for consequent trays? Thanks!

    1. Hi Katie, you don’t have to prepare the empty tray that goes on top of the full one on your worm farm, the tray below gives the worms a warm comfortable home, just add food to the top tray in the usual manner.

  5. Hey cool worms. To expand my farm I gather I would have to split the worms and put some into a new plot .How often would I be doing this ? And would they survive in temps of 40 C . Anyhow time for a worm tea , cheers!!!!

    1. The population of the worms adjusts to the amount of food they have. You only need to split off some of the worm population and add then to a new worm farm when you have an empty worm farm to fill!

      My worm farms have survived temperatures of 40-45 degrees C for several days just fine during a heatwave, just follow the instructions in the article on how to keep your worms cool and they will survive the hottest of summers.

  6. Our worm farm has stopped producing ‘ tea’ we consistently feed the worms and have done for over 2 years. In the last couple of months the worm wee has slowed to next to nothing.what could be a contributing factor ?

    1. That’s not much information to work with, any more details? Water in = water out. My guess is that you probably aren’t putting enough moist materials in there, and the worm farm is also undercover where no rain fall on it.

  7. Hi Angelo.
    Thank you for your excellent website. I was wondering how often you can apply the diluted worm wee to the plants?
    Kind regards. Fran

    1. As we can never be sure of the composition of the worm wee, to much of anything is rarely a good idea, so I use it in different parts of the garden every time to add beneficial microbes to the soil in all parts of the garden. Even with three worm farms and with dilution with rainwater so it’s the colour of weak tea, I don’t get enough to repeat water any spot. If it’s diluted enough you can use it more often, but it’s hard to put an exact figure, I wouldn’t apply it to the same location more than once a week personally, but that’s just me being cautious.

  8. What is the coldest winter temperatures that a worm farm can tolerate? We live in Michigan and get below zero temps in January and February. Thanks for the great information!

    1. Some varieties of compost worms are more sensitive to cold than others, but freezing temperatures will kill them, and depending on the breed of compost worm, their eggs as well. In areas where severe frosts are encountered, a simple solution is to place your worm farms somewhere warmer than outside – in a garage or basement, even indoors. Small worm farms are portable, and homemade worm farms constructed from Styrofoam (polystyrene) boxes work well to maintain the temperature. The wisdom of having smaller portable worm farms that are easy to move around and relocate in areas where severe frosts are encountered should be evident.

      Be aware that in the cold of winter the worms will not eat much, and in very low temperatures they just won’t eat at all, so don’t add any additional food because it will simply just rot.

  9. ?? This has been very informative, I am about to start my first worm bed . ??
    Thank you so very much !

  10. Hello Angelo,
    I am having trouble with my worm farm and I am not sure what I am doing wrong.
    The worm farm I have is the one with several layers and it has been in operation for about one and a half years. Lately I have been having trouble but before that all was going well.
    Recently I found a whole lot of the worms on the floor where I keep the farm in the garage. I took all the worms and remaining bedding and separated the worms from the poo, replaced the bedding with fresh coir and started again. Also at that time the leachate developed a layer of mould on it and it smelt unpleasant.
    All went well for a couple of weeks and tonight I found a lot of worms in the leacheate. They had got there through the tap. When I lifted the top layer there were lots of worms in the base where there is a raised section in the middle for the worms to move to to avoid drowning. I felt very sorry to see that. I cleared the bottom layer of worms and put them back into the tray where the food is. I did notice a small amount of little bubbles on the worm clumps and wondered if this was mucous perhaps? I have also observed some clumps of tiny little light brown insects gathered on the vent holes in the lid and wondered what they were? I only put the food on one side just in case they don’t like it. When I lifted the blanket there were still a lot of worms feeding on the food.
    I have never used another layer in my farm as I was not sure how to do this. Do you put it on the top with a base of paper and more coir? When do I know when is the right time to give the farm another layer?
    Also with the food you have to feed them only after the food given is consumed. I have been collection and freezing the food and then give it to them say every 2 weeks. Is it better to put the fresh food there daily and not to freeze it?
    How often should I place water on the farm? I haven’t been doing this on a regular basis.
    I have read the instructions a few times and still don’t feel confident about managing the worm farm.
    I would greatly appreciate your suggestions.
    Kind regards,

  11. Hi, great article!
    For those worried about low temperatures, my wormery is located in an unheated, 1/2″ tongue and groove uninsulated shed invfront of its window and we often get temperature of below -10c/12f in winter, and the weather is cool and damp in most summers too. I have a dry newspaper on top of the worm bin, it is off the ground, and I keep it on the dry side when the weather turns cold. There is significantly less worms, and therefore worm activity, when cold but the centre of their container (much like the ground outside) seems to stay unfrozen at depth.
    Another thing, if you want compost worms (mine are deep red brandings I believe) there is no need to buy them, simply lay some thick mulch down outside (leaf mold, or partially composted leaves, or some covered veg food scraps) and they majical appear. I have even done this on a concrete slab! You start off with ten, and in next to no time, assuming they like the conditions you provide, you will have populated your wormery.
    Interestingly, I constantly throw food scraps into a large wheelie bin (because it’s conveniently placed outside my back door) and it gets pongy, wet, it smells putrid, throughout the warmer months worms climb the vertical compost walls, no doubt trying to escape the putrid and hot environment, and are to be found in handfulls around the inside rim of the lid, on opening the lid they obligingly drop into my hands to be relocated to the wormery, or thrown back into the wheelie bin with a little potting compost to keep from wanting to escape again – I have been known to throw some wood ash or lime in, but don’t usually bother too much about them.
    Eventually I line a bean trench with the contents (just to get rid of it!) and put any worms I find into the next wheelie bin.
    The cold and poor conditions obviously inhibit the activity of individual worms but even if a colony seems to completely disappear they will spring up again as if from no where and will soon enough be chomping away on the decay. Seriously, I moved some frozen solid (all winter) material from a wheelie bin into a clean container and started “feeding” it with scraps, after a while the little blighters appeared and built up again to significant numbers over the summer, suggesting to me that they smell dinner from afar and migrate, or that the odd veg scrap harboured worm eggs, or that they are quite cold tolerant.
    Any hoo, I only made the “wormery” in the shed because bought in seed compost is getting worse with the municipal recycled products and the inevitable contamination, and I wanted my own seed compost, however, the wormery product, though it looks good was not very successful for seed germination or growing on, even when mixed with peat. Does anyone have any suggestions of what to use the worm casts for other than as a mulch?

    1. Every time it rains, the buckets under the permanently open taps of my worm farms fill up. As I have three worm farms, it takes a while to fill them, it takes about a year or more for a tray of worm castings to be produced, but the end product is worth its weight in gold to plants!

  12. I have a problem with red lice or mites. How does one get rid of them? Apparently they compete for food with the worms

    1. It’s quite normal to have a few mites in worm farms. Is there only a few here or there, which is no real concern, or are their numbers out of control and taking over the worm farm?

      1. There were alot of them. I dried the bin out by leaving it open and in more light. And I only added fine woodshavings, no food . The worms were still fine but the mites dissapeared. After about two weeks I put back a cover and started to add food. Aftet a few days the bin was moist again and the mites double than before. Those funny small white ones as well.

      2. I think the problem may be that there is too much food being added, or the worm farm is too damp, or both. If you use too much starchy foods the bedding becomes quite acidic, favouring the mites. What are you feeding the worms?
        I wouldn’t have used wood shavings in a worm farm to be honest with you, woody material takes way too long to break down, when soft woods like pine break down they release chemicals toxic to plants and worms, and and woody materials don’t belong in a worm farm at all, they should go into your compost. If you want to soak up some of the water, add a whole newspaper in there as a cover over the food. Is your tap left open with a bucket underneath to drain out the liquid?

      3. I’m replying from this answer, I couldn’t from your last one.
        I might over feed them. Mostly potato and carrot peels. The wood shavings are very fine, more dust than shavings. I must say that the worms work through them in good time. This bin is my first one and has only been going for a few months. Its a selfmade one from catlle lick tubs. One on top of another. The top one has holes on the bottom from drainage. But up to now nothing has dripped down.
        I see we have a bit of a time zone difference. I assume you might be from the USA? I from South Africa

      4. Hi Johan, if you feed your worms moderately to start off, then gradually increase the food you give them, their population increases to match the food supply. If you cover the food with a ‘worm blanket’, a damp hessian sack or moistened whole newspaper, it will encourage them to come up and eat the food. Chopping the food scraps finer also allows the worms to consume it faster, compost worms and earthworms don’t have teeth. Throw some crushed up eggshells in there occasionally, they help neutralize acidity and supply the worms with calcium, it’s an important mineral for the worms.

        I’m in Australia, southern hemisphere much like you, just a different latitude!

    1. That would make an earthworm smoothie! I’m not kidding, I’ve seen articles and videos where people wash earthworms and put them in a blender with other ingredients to make a protein-rich smoothie.

      Why would you want to crush up your compost worms? Your worms are more value to you alive and happily composting your kitchen waste. Do it for the worms! : )

  13. Do worm farms have to have air holes, and if so where should the holes be? Also is plastic or wood better for their home?

    1. Worm farms must have air holes to let air in and heat out, holes should be at the top of the lid as heat rises.
      Plastic or wood is equally suitable, be aware that wood will rot, some wood faster than others, and worms won’t like painted wood, treated wood, or certain woods that release oils such as pine.

  14. Hello Angelo, I have a new worm farm made with a broken vertical freezer. I am wondering why the worms are trying to run away from it. I am following your instructions.

    1. All my three worm farms are the same size, two are square and one is round, please see the descriptions below the photos.

  15. Hi there, how much often to water the worm farm, 2 times daily or 1 time daily. Im from Malaysia, thanks for your help!

    1. Thanks for your question. Worm farms don’t need much water at all. The bedding layer should just be barely moist, like a wet kitchen sponge that has been squeezed out. If the worm farms are exposed to rain, they won’t need much watering except on hot summer days. If you’re in a tropical climate and things take a long time to dry, you won’t need to water too often.

  16. Help! I have two worm bins. I’ve had them for years. I feed them the same food, just smaller amounts to the smaller bin. I have a new problem. The smaller bin seems to be killing the worms. I have an abundance of “pot worms” which I read was an indicator of the dirt being too acidic, so I’ve been adding lime. Now, the dirt has a pH of 8-10, but there are still a ton of the little white worms, and the new worms that I added seem to have mostly died. I’ve bought new worms twice, and now I’m afraid to do it again because I don’t want to kill them.

    The worms in the larger bin appear healthy. The worm dirt there has a pH of 8-9.

    What should I do?

    1. i would not have added lime, but rather reduced the amount of food that was added to the smaller bin, and added a few egg shells for calcium and very slow release of lime. Not sure what you’re using to test pH, but each step in pH is an increase of ten time, two is a hundred times more alkaline from pH 8 to pH 10. If it’s really anywhere near pH 10 and no worms are left alive in it, I would dump the contents in the trash (not in the garden) and just start afresh to re-establish the worm farm from scratch.

  17. Please can you tell me how long it will take for the new worms to produce babies. i bought 500 small fresh worms and they have been with me now for 6 weeks. They are looking so much bigger but I am not sure when they will produce a new generation.

  18. Hi
    I’ve just established mulitpe worm tunnels around my garden, but as I live on my own, I need to get creative about what to feed them. I’ve been giving them garden refuse (mostly green) as well as kitchen scraps, and a little straw. Any other ideas?

    1. In the article I mention a dozen items that can be put into worm farms:

      Fruit & vegie scraps
      Bread & cheese
      Cooked vegetables, grains, pasta & rice basically all vegetarian foods, no meat-based sauces!
      Coffee grounds & tea bags as long as teabags are paper and not plastic mesh
      Egg shells great source of calcium, a mineral which worms require in their diet to stay healthy
      Newspaper & unprinted cardboard (soaked) no glossy printed pages

      I also like to put comfrey and borage leaves into my worm farms, as they’re very nutrient-rich.

      If you have a water garden, the azolla (fairy moss) and duckweed can be scooped off and used in the worm farms, as can aquatic plant prunings from overgrown water gardens.

      Hope that helps! 🙂

    1. Yes, vermicomposting (worm farming) using compost worms or earthworms is exactly the same, the only difference being that earthworms only eat half the amount of food that compost worms do.

  19. Hello!

    Can I use my aquarium water to rinse/water the worm bin? I use it on my plants and it is also good for non-wormed composting, so I was wondering if the nutrients and waste from the aquarium water would hurt the worms? It is freshwater that is treated to remove chlorine, this would be the “dirty” water taken out for tank cleanings.

    Thank you!

  20. My work farm has two trays and is well established, mine love banana skins and pulp, mangoes and avacardos, all at different times, in Melbourne’s winter I use large pieces of polystyrene that was packaging from an appliance. And in summer I flush every second day, and I have never had any issues,plus I have never used paper or cardboard and this is a surprise to me that you can put in cooked vegies. So thank you for all your information, it’s a greatly appreciated.

  21. Thank you for the article and for all the useful information you have provided.
    A question:
    Is there sufficient oxygenation inside the composter made in a bathtub?
    Thank you,
    Orvieto (Umbria, Italy)

    1. The large surface area of the bedding material provides good oxygenation, just make sure that the cover used doesn’t seal the bathtub and allows air circulation. A piece of fly screen or shade cloth on either end of the bathtub will help with airflow.

      1. Fine thanks! I had some doubts because I saw that someone puts inside a plastic tube with holes to let air in …

      2. Well, almost right… Vermiciomposting is just another name for worm farming, and it’s done in a worm farm with a worm bedding tray with a liquid-holding tray beneath it, and compost worms in it which break down fruit and vegie scraps. Compost bins use bacteria to break down garden waste! 🙂

  22. Hi.
    I have a multi tier worm farm.
    Currently, there is the base, with tap attached and the tray on top which has castings, worms and food.
    It looks like your diagrams but I note that in your photo’s there are three trays total?
    Should I have the base tray to collect water, then two trays on top of this?
    Just starting worm farms so any help is appreciated.

    1. Hi Kirsty, my worm farms have the base tray which collects the liquid, and two worm trays above those. Start with one worm tray, and when the worm castings reach the fill-line on the inside of the tray, and don’t seem to go down any more, which can take many months or a year, add the second worm tray. When the top tray begins to fill up, so there’s enough materials for the worms to live in, you remove the lower worm tray, take the finished worm castings out, and keep it aside. When the current worm tray reaches the fill line, place the empty worm tray above it and repeat the process. Hope this helps! 🙂

  23. Hi…I live in the country and I have several worm beds…I just put brick in a square and layered leaves.. shredded newspaper.. dirt.. worms Ive dug up… and they are chock full.. and theres babies everywhere.. like in the tea bags.. but I need the dirt… its thick and ready. How am I gonna do this? Heeeeeeelp!!!!

    1. Use the pyramid method to remove worms from completed worm castings. If you can still see the tea bags in it, it’s not ready yet! The completed worm castings will always be at the bottom of the worm beds, that’s where you have to take it from.

      If the weather indicates that rain is coming, the worms will naturally move to the upper layer, they can sense the drop in air pressure that occurs when rain is coming, that’s how they avoid drowning. During this time it’s easier to dig out completed worm castings from the lower levels, and if there are any slower worms in there, use the pyramid method to separate the worms from the castings.

      Hope this helps! 🙂

  24. Thank you for this information: its simple, to the point and easy to follow.

    One question I do have, when you mention that the composting worms are surface feeders and thus cant burrow deep, what measurements would you attribute to surface?

    I have wicking beds, raised beds and obviously compost bins that are about 1 meter high. As the earth worms multiply, I would like to add them to the compost bins.

    1. You can get live worms for your worm farm from garden centres, but if you can’t find them, many fishing stores sell compost worms as bait, but they cost much more, and you get less worms!

  25. Good afternoon. The how to make a worm farm sounds refreshingly simply Ref worm farms in a bath is a shade cloth liner simply hessian or similar?
    Will definitely do it.

  26. Hi All i just got my new Worm farm & did well but now noticing my worm going all the way down into the base thru the tap & some are in the Bucket I have moved some back into top section,what do i need doing ?? asking friends ??

    1. Is this a new worm farm, or an established one?
      What have you put into the worm farm that they dislike so much?
      They’re obviously trying to escape and environment that’s not good for them, putting them back in won’t make them happy!.
      If you’ve put way too much food in there, more than they can eat, and it’s going foul, you’ll have to remove it.
      Need more information to figure what’s gone wrong.

    1. You wouldn’t buy 30kg of worms, it wouldn’t be financially viable, you would breed them up over time. First, you create a a worm farm system or series of worm farms that can support 30kg of compost worms, which is an enormous amount. Then you buy a small number of worms, put them in, and let them breed for a year. A regular home worm farm will hold about half a kilo of worms when its full and well maintained, to give you some idea of scale you’re talking about.

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