Digging, mud and manure are not things that I have ever relished about gardening. Some people find it very therapeutic to get dirt under their fingernails and turn over every square inch of their soil at least once a year. Not me. I started life as a bit of an indoor child and moved on to computer programming, so it’s been quite a surprise to find myself enjoying growing food outdoors.
But there’s one thing that does motivate me to get my hands dirty: compost. For many gardeners compost is a sort of side-benefit from the big heap of old weeds in the corner of the garden. But I like to be far more methodical about it. Search the Internet and you will discover that there is a whole science of compost and even a variety of recipes. In fact, it really is a bit like cooking – there’s an art to finding the right ingredients, producing the best mix and getting it to ‘bake’. With the right attention a compost heap can reach temperatures of 70 degrees Celsius/158 degrees Fahrenheit which has two important advantages:
- The compost is ready in about a third of the usual time, meaning that you can start it off in autumn and have it ready to use the next spring
- At these higher temperatures the weed seeds that inevitably form part of the compost mix will be sterilized
So what are the magic ingredients? There’s some very good advice at Garden Organic’s website but a basic summary is:
- A good mixture of ‘green’ material (weeds, remains of plants, grass cuttings, vegetable peelings etc) and some ‘brown’ material (sawdust, shredded woody plants, leaves)
- The right amount of water: it should feel damp but not soggy
- For the best results, the heap should be approaching a metre cubed (35 cubic feet) in size and built in one go. Materials to go in can be stored up for a few weeks and then mixed together. This ensures that it’s all heating up at the same time which helps you to achieve higher temperatures
- Air – never squash down a compost heap and aim to turn it over with a garden fork each week for the first few weeks. Having a couple of compost bins next to each other can make this much easier - you just fork the material from one bin into the other one
- The smaller the materials can be chopped the better the results. A shredder is ideal but does take a lot of time
If you want to get very scientific about it you can purchase a compost thermometer which has a long probe that you can plunge into the heap to see how hot it gets (yes, I have one!) But the most satisfying thing for me is plunging in a garden fork on a cold autumn morning. It is very satisfying to watch the steam rise as if by magic from nothing more than scraps of garden waste.