Permaculture is all about working efficiently and in harmony with Nature. We can garden far more efficiently, with far less effort, and improve the soil at the same time by emulating Nature’s soil building processes through practising Chop and Drop gardening.
How do most sustainable gardeners garden? At the end of each season, many gardeners pull up all their annual vegetables which have finished up and thoughtfully put them into the compost, then prepare the soil for the next season. As part of that soil preparation, finished compost from many seasons ago is usually retrieved from compost bins and dug into the garden beds along with some manure. Mulch is usually purchased and laid over garden beds in late spring to conserve soil moisture during the peak of summer heat. The cycle repeats each year, season after season…
Is there an easier and possibly better way to manage a vegetable garden full of annuals? Perhaps Nature has some answers!
WWND (What Would Nature Do)?
When I do talks about Permaculture, which in essence is ecological garden design, for the sake of perspective I always like to begin by reminding people that Nature has been growing plants for 460 million years and trees for 370 million years, whilst modern humans (Homo sapiens) first appear in the fossil record in Africa about 195,000 years ago, and agriculture was invented relatively recently around 10,000 years ago. It’s safe to say that Nature has been managing plant life for quite a while, and we’re quite new to the game.
If we look at how annual plants grow naturally, seeds land in the soil, plants emerge and grow, and if they’re not eaten, they flower and possibly fruit, produce seed and then die down, eventually decomposing and releasing their nutrients and organic matter back into the soil. The roots rot down below the soil, opening up air and water channels which loosen the soil and help water penetrate deeper down. The dead plant matter on the soil surface creates a mulch, which further gets covered with fallen leaves, and breaks down into the soil. Earthworms feeding on the rotting plant matter dig it deeper into the soil and by digesting it transform it into highly fertile worm castings, possible the best possible plant fertilizer ever created.
As each layer of plant matter gets deposited on the soil surface, the bottom-most layer rots down first, then the one above it. New layers are always added to the top each season, creating a continuous soil building process without any digging or human intervention. It’s quite impressive! Over decades and centuries, the soil level increases, as does the fertility of the soil. That is what Nature does.
How to do Chop and Drop Gardening (Sheet Composting)
We can emulate what Nature does through the technique known in the Permaculture world as the Chop & Drop system, which is essentially sheet composting. How does it work? It’s quite simple.
Chop and Drop Gardening in 4 Easy Steps:
- At the end of the gardening season, don’t uproot any vegetables that have finished, but chop them off at the soil level, leaving the roots in the ground.
- Drop the plant tops on the soil surface – lay them down whole, or cut them up into smaller pieces first, by either using secateurs, placing then on a concrete floor and chopping them with a spade, placing them in a clear area and going over them with a lawn mower, or feeding them through a garden mulcher.
- Add a layer of manure.
- Cover with mulch, such as lucerne, pea straw, sugar can mulch, etc.
That’s all there is to it, I did promise it was easy! There’s no carting plant waste or compost back and forth, the nutrients go directly back into the soil, it’s very efficient.
Because the plant material, manure and mulch are all laid down in this layers or sheets, this is referred to as a sheet composting system. It’s a great way to save space as you don’t need dedicated composting areas in a garden, because the whole garden becomes a huge sheet composting system.
In case you hadn’t realised it already, this is also a no-dig gardening system. The digging is taken care of by earthworms feeding on the decomposing plant material, and soil aeration is further assisted by the cut plant roots rotting down below the soil, opening up new air and water channels, allowing water to penetrate deeper into the soil.
The Chop & Drop system is very versatile, it works with much more than just annual vegetables though, it’s excellent for trees too, but it works differently, you don’t chop the tree down thankfully!
Tree Chop & Drop
If you have fruit trees, an orchard or a whole food forest, you will need to prune trees. What to do with all the tree prunings? Mulch them and place them under the tree that was pruned, then throw some manure over the top to help it all break down. It works well, I’ve been doing it for over ten years now!
If you want to dress it up, place a layer of straw mulch around 5cm (2”) thick over the mulched prunings and it will look nice and tidy, good enough for a show garden. I did this with my urban food forest garden for the Australian Open Garden Scheme which presents the top tier gardens nationally, and of the many hundreds of people who visited over a single weekend, nobody had an clue what was under the neat and tidy looking mulch!
By placing mulched prunings below trees, nutrients are recycled in situ, enriching the soil, and saving on soil amendment materials. The woody material breaks down to create a very stable humus, and encourages mycorrhizal soil fungi which associate with tree roots and assist trees in accessing minerals and water beyond the range of their roots.
If prunings are way too big to mulch, large branches and even logs can be composted using a system know as a Hugelkultur bed. There’s always a sustainable and energy efficient way to processing any garden waste.
Chop and Drop or Rip Up and Compost?
Are there plants that shouldn’t be chopped and dropped? Actually, yes there are!
During some research on companion planting, I discovered that brassica cover crops grown as green manures suppress weeds during autumn by virtue of their vigorous growth, and after they’ve been chopped down and dug into the soil, their residues inhibit small seeded annual weeds. I also found that traditionally, turnips were planted heavily and left to rot down to clear areas of weeds. That’s because the brassica/mustard family (cabbages, cauliflowers, turnips, radishes, mustards, etc) are allelopathic, they release compounds which suppress seed germination and plant growth (including weeds) when they rot down. So, it may be a good idea to rip up these allelopathic plant and compost them before preparing the garden beds for warm season vegetables, or they can be left to suppress weeds if nothing else will be planted for a while.