I’ve been thinking it’s time I setup a composting system at our new house (we moved three and a half months ago), so I’ve been reflecting on my past composting practices, my knowledge of other composting systems, and how we’ve been living in our new surrounds to figure out what will work best. I’ve also been strolling around the farm looking for salvageable materials to build it. But, it wasn’t until I started thinking about where the best location was that I realised I didn’t need a compost bin, bay or heap at all. It should have been obvious, given my biodegradable waste has not been going to landfill the whole time we’ve been here and in fact, my previous compost system didn’t produce any compost above ground level in the three years I used it!
Why I don’t need a compost unit
- We are good at making as little food waste as possible. Our family of four fills our 4L kitchen caddy on average twice a week. This is markedly different from the average household which fills their landfill bin with 40% food waste each week. That’s 48 Litres for a 120 Litre bin compared to our 8Litres! I don’t leave any food types out of the compost caddy. Dairy, bread, meat, and oils all go in there. It’s important to note that these are miniscule amounts because we don’t waste food and we have reduced our meat intake.
- We have a dog who can eat some of this stuff, but she is rarely treated to it because we rarely have the waste. The only bones we seem to have had for several years is the occasional chicken carcass. It’s dangerous to feed dogs cooked bones so we don’t do this.
- Instead, I use the bones to make stock or bone broth after which the bones disintegrate easily. I add the crumble to the kitchen caddy.
- We also have chickens so I scatter the contents of the kitchen caddy in the chicken yard. The chickens do a good job of cleaning up the scraps, even the chicken bone remains, but things like mandarin peel and corn cobs get left behind. This stuff will continue to biodegrade where it is but it does look messy after it’s accumulated and I don’t want to encourage pests, so I will rake it up and bury it directly in the garden – this is known as dig and drop composting or trench composting.
- Occasionally we have other compostable waste that is not reusable or recyclable, like bamboo ear buds, cotton rags, and reused parchment butter wrappers. I have been putting them in our wood heater this Winter. I can’t see anything wrong with this because we are recovering the energy in these items to heat our home and the remaining ash gets spread throughout the gardens when the fire box is cleaned out. Obviously, we can’t do this in the warmer months so that’s when I dig and drop them (here is my post on composting old clothing).
- Then, there is the organic matter from tending to gardens. Prunings, leaves, deadheads and spent plants can be pulled and dropped or cut and dropped in garden beds to biodegrade. Larger pieces can be cut up further with secateurs or mown over.
- Difficult weeds are drowned to kill them completely and to create weed tea fertiliser before the remains are discarded discretely on garden beds to break down, but they could be buried too.
- Finally, we don’t have to compost dog poo because our dog runs around free on the farm all day and she does her business in the paddocks. However, you can dig and drop dog poo too. The chickens are also free range but the poo from the chicken house is spread around the fruit trees to fertilise them.
How to dig and drop compost
Above, I’ve highlighted in green the only two circumstances where I actively want to compost using the dig and drop method. There is not a lot of organic matter for each of those circumstances so digging a hole suits me better than digging a trench. You can get really organised with trench composting and rotate the trenches with garden beds if you want but I want absolute simplicity, so here is how I’m doing the dig and drop.
- Dig a hole. This could be in an ornamental or vegetable garden or in a raised garden bed. The hole can be as wide as you like but it needs to be deep enough to protect the compost material from pests, but not so deep that nutrients are leached into ground water. Getting the depth right also keeps the compostable material in the biologically active zone with all the worms and microorganisms. Gardening Australia suggests digging trenches to no more than 35cm deep or 25cm if you have heavy clay soil, so my holes will be dug to 35cm.
- Drop organic matter into the hole, approximately 20cm deep. Don’t compact the scraps as the air spaces are important for providing oxygen and habitat for the soil organisms. A diversity of materials is best to include if you can.
- Replace the excavated soil. This should be about 15cm of soil on top. Decomposition is pretty fast so you can even plant seeds and small seedlings on top.
That’s it! I won’t need to dig new holes very often because of the small amount of material needing composting. I even use a lid to cover the hole to keep pests out until it is full enough to top with soil.
Doing this reminded me of a Gardening Australia episode I saw last year, so I searched for it and found it under Costa’s free range worms fact sheet. It’s essentially Dig and Drop composting except he uses a bucket with holes to contain the scraps and allow the worms to come and go as they please. It’s a cool idea but if you ask me, Dig and Drop composting is the ultimate for free-range worms.
The benefits of dig and drop composting
Dig and drop composting has a lot of benefits over other composting methods, including:
- It saves space in the garden. Digging holes is a great solution for people with small yards.
- There is no smell (not that I have ever had that problem).
- It’s very frugal. All you need is a shovel. There’s no expensive units to set up or ongoing inputs to purchase like bokashi bran.
- It’s zero waste. There are no end of life issues to manage as with plastic bins and worm farms.
- It’s less work. There’s no ratios of browns and greens to worry about, less raking and carting of garden materials, no turning necessary, no need to think about moisture levels or pests, no need to harvest and distribute the compost because it is already in the ground doing it’s job!
- Decomposition is fast because the contents is well insulated and kept moist, and all the microorganisms and worms have direct access. Most things will breakdown in one month to six months. If you want to speed up the process, cut up the organic matter or process it in a blender first.
- It deters pests.
- It’s great for neighbouring plants and it improves soil, especially in compacted areas.
Do you, or would you use dig and drop composting and free-range worms?