Hooray for long weekends! This long weekend I helped some friends construct their own compost bin/area/secure heap.
It’s certainly true that if you leave a pile of organic waste in a heap it will eventually decompose, but a compost bin can speed up things considerably. Another important aspect to composting in our urban environment is that we don’t want to encourage or feed vermin. There are of course many ‘off the shelf’ options for compost bins, each presenting particular advantages but I was confident that we could build one from materials I already had on hand, and that it wouldn’t even be too much hard work!
- 6 or so wooden stakes (in our case, straight branches salvaged from a pruning job)
- small gauge wire mesh – sometimes available at the green shed for a few bucks!
- carbon rich feedstock material – dry leaves/shredded newspaper/straw
- coffee sacks or similar for covering heap
- shade cloth or similar for lining (optional)
- tools for digging, gloves and a sunhat!
Our site was a disused corner of the garden, tucked in behind the veggie patch.
(Please excuse the poor quality photos, we were too excited about constructing!)
First we dug a shallow hole. The old pitchfork proved very useful to loosen the clay and get around the many rocks. I just kept hitting the spade against rocks!
Then we constructed the ‘fence’, the stick and wire walls of the bin. Rather than trying to drive the sticks into the hard, clay ground we simply stood them up around the walls of the hole and then back-filled with soil. Little hands are great for patting and compacting the soil around the base of the sticks. Then we wrapped the wire around the stick frame as tightly as we could, and secured this with some garden twine.
Seeing as we found so many rocks in the dirt patch they were added back around the base of the structure for a decorative touch! On top of the soil inside the bin we placed a square of shadecloth material that I had handy, this should just help some of the compost fines and nutrients from leaching away. It was loosely placed in though, so hopefully any worms that would like to move in can still get around the edges!
To finish it off, we dumped a whole load of autumn leaves into the bottom. This is mostly a pest deterrent! Mice or rats could probably still dig into the bottom of the heap, but they won’t have much incentive if all that they will find at first is a pile of dry leaves. Hopefully this is enough to deter them from digging in further to find the nitrogen rich veggie wastes anyhow! After this deep layer of carbon rich materials, the compost heap will be built up with alternating thin layers of nitrogen rich kitchen wastes (and some urine soaked kitty litter!), and thin layers of carbon rich materials. It is a good idea to have a pile or large receptacle of leaves etc next to the heap for this purpose.
We also placed a reclaimed coffee sack onto the top to protect it from above, this should also help with temperature regulation, and keep a bit of a lid on the occasional odour.
In the end we were pleasantly surprised by the structural integrity of the new compost bin. It’s only small, so may not be able to perform as a super-efficient hot composter, but it should be relatively easy to use. With a careful eye to layering of nitrogen and carbon rich materials, and keeping an eye on moisture levels, it should be able to carry out some decent degradation. It may not reduce all of the contents to ‘finished compost’ but that’s ok, as portions can be buried in the veggie patch before they are fully degraded and that will still be a valuable soil amendment.
A question that the new owners had for me: “how do we get the compost out of the bottom?”. The best way is going to be lifting up the fence/walls, at which point you can get stuck in with the pitchfork. This is what you usually end up doing with the plastic walled compost bins anyhow, even if they come supplied with little doors at the bottom. That will be a job for spring I think, and I’m sure I could be convinced to help once again 😉
With some simple materials and not a whole lot of brute strength a couple of ladies (and some eager mini helpers) got this done in a few hours. I’m hoping the owners will enjoy disposing of their kitchen wastes into the new heap and enjoy watching it transform.