How to make perfect compost
Recycling garden waste is good for you, your garden and the environment, and is a very satisfying process as well. Best of all though, is the realisation that you'll have the last laugh on all those pesky weeds as you turn them into something really useful.
How to do it
Making compost is really very easy, but for reliable results you need to understand the principles behind the process so that you can manage it effectively. In essence, making compost is like making a cake: you have to have certain equipment, the right ingredients in particular amounts and then add water and mix thoroughly before ‘cooking’. The soil-borne micro-organisms will then do all the hard work for you. For a well-done compost, ‘cooking’ can take anything from a few months to a year, depending on the material you use, the time of year you start (rotting is quicker in summer than in winter) and the sort of compost you want at the end of the process.
- What do you need? You need a bin, a variety of organic waste materials and a little patience.
- What size bin? A bin is essential to keep the material neat and tidy and to help retain moisture and heat. Choose one to suit the size of your garden. Ideally, it should be about 1m³ which holds sufficient material to compost efficiently. Smaller bins can work well, but require more careful monitoring to keep the conditions right for decomposition. If your garden and household doesn't produce sufficient organic waste to fill a bin of this size, consider getting together with gardening friends and neighbours to produce a communal composting bin.
- How much waste? Aim to fill your bin as quickly as possible, because the decomposition process won't start in earnest until the bin is full. In practice, most successful composters fill their bin in about a month. So, in a large garden you may need two, three or more bins to recycle all your waste.
- What can I compost? To get quick decomposition you need to have the right ingredients in the right proportions. A balanced diet of dry fibrous material (such as shredded prunings, newspapers or straw) and wet green material (such as grass clippings, discarded bedding and weeds).
- Can I add woody prunings? Yes, but all woody material needs to be chopped finely before it is added to the compost bin otherwise it will take longer to decompose than the other ingredients. The easiest way to chop it up is with a garden shredder, but if you have the patience you can get the same results with a pair of secateurs. · What should I avoid in my compost heap?
- Fat Thorny prunings
- Glossy magazine paper
- Plastic-coated cardboard
- Conifer and other evergreen material
- Perennial weed roots
- Flowering weeds
- How long does it take? Compost started in the autumn can be ready for spring planting, but most people usually leave their compost heap for a year. In ideal conditions during the summer, the compost bin you filled at the beginning of May will be ready to use by the end of July. The final compost bin filled during mid-summer should be ready to use in the autumn.
Why can’t I compost these?
Processed food products can attract vermin, weed roots and seeds may spread around the garden, sawdust may contain toxins, and cardboard, woody or evergreen material takes too long to rot down.