Compost is something every serious food gardener should understand and practise, says expert gardener Jeni Foster.
Organic matter is the mantra for all successful gardeners. It is the most important element for healthy soil structure.
You can add organic matter to your soil as manure or compost. There are some excellent ready-made composting systems you can buy to make composting a simple, neatly contained business and take all the guesswork out of it. If you want to do it yourself, however, and get into the science of composting, there are some guidelines that must be followed or you’re doomed to failure.
First of all, it’s important to lay compost and mulch during autumn to help keep the soil warm as winter is approaching. This should clean out your existing compost and provide space for you to organise your next batch. After the spring and summer crops have been harvested and leaf drop begins from deciduous plants, you should have plenty of material in addition to your kitchen scraps to compost.
The basic rule to composting is a 30 (carbon) to 1 (nitrogen) ratio. Use your nose to troubleshoot problems. If your compost smells bad, add carbon and coarser material, then turn for aeration. If it smells good but is not breaking down, increase the size of the compost heap (should be least a cubic metre). If it is still not breaking down, add more nitrogen material and check that it is not too dry.
Moisture is an important factor as micro-organisms that bring about decomposition love water. Your compost heap needs to be moist but not wet, so it’s a good idea to cover it. This will keep moisture in and rain out. If your compost heap becomes too wet, add dry material, such as leaves, and turn the pile. Aeration is also important for your compost heap, so make sure you turn regularly and insert a perforated
Quick compost method
- Build your compost heap to a minimum of one cubic metre by laying each carbonaceous and nitrogenous materials, keeping the 30:1 ratio.
- Water each layer as you go.
- Make sure you keep it as light and fluffy as possible. A sprinkle of organic blood and bone throughout the heap is a good helper.
- Insert PVC pipe and leave for three days. Your compost heap should heat up to around 40ºC.
- After day three, turn your compost heap every second day for 2–3 weeks, depending on rate of breakdown, and moisten if needed.
Plants for your compost
Plants can be grown specifically to add to your compost or to make compost tea. Yarrow, comfrey and nettles are wellknown compost activators and should be grown around your composting area. Not only do they hasten the composting process they also provide valuable nutrients. Yarrow is a good source of copper, comfrey is rich in potassium, nitrogen and phosphates and nettles provide iron and nitrogen.
Compost tea recipe
- Fill an old stocking with a combination of yarrow, comfrey and nettles.
- Place in a bucket of water.
- Stir every day for two weeks to keep it oxygenated.
- Dilute half/half with water and apply to your garden.