Composting – Part One
Compost should always be well rotted. The wisdom of this was classically illustrated a good few years ago at a time when my wife and I were in a folk group: we stayed overnight in a bed and breakfast somewhere in Yorkshire, near where we’d done a gig the night before. Unfortunately, the thin walls of the bedroom, combined with the noisy activities of the people in the next room, led to a sleepless night. They appeared to be working their way through the Karma Sutra and, by the sound of it, merited a place in The Guinness Book of Records for managing the whole lot in one go. However, the disadvantages of the place left my mind as we were leaving, because a sign on the wall outside offered free horse manure. Any serious gardener will recognise that my bliss on discovering this was greater than that of the bloke in the next bedroom. The owner gave me a large number of plastic bin bags which I filled and stored in the back of the Renault Estate. Then we started for home.
The timing of this event could have been better, because it coincided with the hottest day of the year. This caused the compost to react with unnecessary vigour and my wife threatened divorce as, even with the windows open, we levitated along the M62 in a blue haze. Eventually I gave in, stopped the car and dumped the compost at the edge of the hard shoulder. I often think back to how subsequent motorists, seeing that steaming heap, would think it must have been a bloody big horse that did it.
The point is, compost should be well rotted before adding to the soil – the bacteria which break it down initially need nitrogen butties to give them the energy to work and they take them from the surrounding soil. This leaves nearby roots short of that nutrient and the plants exhibit symptoms of deficiency, like browning leaves. Gardeners refer to this as ‘burning’ and death can follow (of the plant, not the gardener). Well- rotted compost doesn’t smell. It is also black and crumbly.
With the best will in the world, people often start a compost heap and don’t recognise that something isn’t quite right until they end up with a towering, unstable pile. This may be rotted at the very bottom but certainly isn’t at the top and the only way to get the good stuff out is to risk an avalanche. The obvious answer is to have two heaps – one covered with old carpet or plastic bags while it breaks down and the other open for new additions.
|One heap breaking down, the other being built up|
The covered heap should be insulated as much as possible to keep heat in, while also allowing oxygen access. It should be moist, though not too wet and there should be a good balance of green, leafy material and woody stems. It should also be turned occasionally, allowing the outside to get rotted.
Composting is an inexact science and a bit like baking, in that sometimes the cake inexplicably doesn’t rise. There’s a lot more to it , and part two will look at the role worms sometimes play. It will also feature their sex lives. Calm down.
|Kitchen waste bin next to door|
If anyone has questions about composting, or other aspects of gardening, don’t hesitate to ask.