I’ve spent several days over the past three weeks dealing with the compost heaps: Co-operative and crumbly (well – getting there, at any rate!), nicely bedding down, or recalcitrant and smelly – you name it, I’ve turned it.
In my family, no-one ever turned the compost. Stuff from the kitchen and the garden was dumped onto two or three heaps far from the house itself. The piles were contained in makeshift, 3-sided wooden pens, latterly in similar containers made of wire netting. Then they were left to get on with the job of rotting down. No drama!
No-dig organic gardener and educator Charles Dowding describes compost-making as an “alchemical process that degrades almost anything.” Mesmerised, I watched a video on his website* of how he goes about making huge quantities of compost for his market garden in western England. His approach? Almost any plant material goes in, even roots of weeds such as couch grass, provided the heap is added to regularly, thereby smothering the roots. Temperature and moisture levels are kept optimal, and the proportion of “green” to “brown” is roughly 50:50.
Getting the right mix of “green:brown” is the fundamental principle underlying all good compost-making. Ideally, aim for the ratio above, or even for 25:75.
In Egypt, my results are somewhat mixed, I don’t know why. It can go according to plan:
But it may not:
The third bin, which was filled over the winter, contains a seriously nasty sludge, very wet and unusually pungent. My instinct is that its rather acid smell may indicate too much citrus fruit waste. The excess moisture means not enough air in the mixture. Dowding’s rule is that you should not be able to squeeze any liquid out of the mix: By no means an activity I enjoy, squeezing this lot gives it away.
So here’s the lowdown on my composting method:
Containers: There are five bins, none of them large. One is made out of wood from freight boxes and measures 42cm x 35cm x 60cm high. It is lined with cardboard – a material that never seems to rot down. Then there are four plastic bins, also 60cm high, with drainage holes pierced in the bottom of each one. None of these is lined, but I usually start with a network of woody twigs and stems at the bottom to protect the drainage holes.
Contents: We recycle all the plant-derived waste from the kitchen. Peel and chunks of vegetable/fruit are cut up into small pieces (by hand!) Coffee grounds can be included: they are also “green”. Debris from the garden goes in, some in the form of fresh clippings and fallen leaves. Then there are loads of chopped woody stems and twigs (brown material). As far as possible, I dry these in the space between the raised beds and as soon as one load of dried matter is moved into the bins, in comes a new batch of fresh waste:
Bugs and weeds: There is a view that you can compost anything, even clippings of (for example) hibiscus, geranium and roses after the mealy bugs have invaded – weeds will be smothered by a good-sized heap, and pests cannot take the heat in the, er, compost-kitchen. I’m not of this school of thought: I don’t compost pernicious weeds, and I think infested plant materials should be burned. So I do sort the waste before I compost it.
Temperature: I don’t have a thermometer I can use in the compost heaps, but I note that Charles Dowding is careful to measure the heat. Ideally, you should aim for 55C-70C. Above 60C, most pathogens and weed seeds will die, he says. I’m pretty sure our compost gets a good deal hotter in the summer months as the bins are in full sun through the middle of the day. The final product may have been pasteurised for all I know!
And finally… Are you all for turning? I am! Mr Dowding considers it to be optional, but advises it will introduce more air into the mix, keeping the useful bacteria healthy. You will also break up any clumps of matter, aiding the degrading process. What you get, in 6-8 months’ time, should be a gorgeous, dark(ish), crumbly organic mixture, both light to the touch and rich to the eye – truly, a gardener’s feast!
* For Charles Dowding, see: http://www.charlesdowding.co.uk