Composting is the cheapest and best method of getting organic matter into your garden soil but it's really important to choose a method that best suits your situation.
What most gardeners might consider a proper compost heap is one that reaches up to almost 70 degrees Celsius. That's enough to kill weeds or any diseased material and the whole thing breaks down within a matter of weeks. It takes a lot of work to get the heap that hot. You need the right balance of nutrients and moisture to encourage the beneficial micro-organisms that provide heat. You've also got to turn it constantly, every few days to get enough oxygen into it for the micro-organisms to work. Otherwise, the heat can become stagnant. You also need about a cubic metre to get the heap really hot and the average suburban gardener usually doesn't have that much organic material lying around at any one time. But there is a great practical alternative - the cold compost heap. The cold compost heap is perfect as most households generate kitchen waste everyday. Just pop the waste in and cover it with some bulky material, such as lawn clippings, or even shredded newspaper to discourage fruit fly. I'm particularly proud of the compost bin that I've made out of some scrap timber. It has a trapdoor at the base to allow access to the beautiful brown compost, which is ready to go straight onto the garden. It's possible to compost anything that was once living. However there are a few dos and don'ts with a cold compost heap. For instance don't put in things such as perennial running weeds, like kikuyu and couch grass. Or bulbous weeds such as oxalis and onion weed. The heap won't get hot enough to kill them and they'll re-sprout and cause problems later. Also avoid meat scraps, because they smell and attract vermin. People often ask about using citrus peel, onion skin and eggshells in the compost. In my experience, they're not a problem. Just dice up the citrus peel and onion skin and crush the eggshells before they go in. Another golden rule is to alternate the nutrient levels between different layers. After adding kitchen scraps, which are high in nutrients, follow with a layer of something like dead leaves. Remember that things like shredded newspaper are low in nutrients, so nutrients on either side will help it to break down. My favourite high-nutrient material is manure, that's the icing on the cake. One of the major problems with cold composting can be a lack of aeration. For instance, if you put in too many kitchen scraps at once, it can mean an anaerobic or oxygen-free environment. This turns the heap into a stinking mass which favours soldier-fly larvae or maggots, and that's not what you want. An easy solution is to aerate the heap with a rigid PVC pipe, which is drilled with many holes. Just drive that right down into the centre of the heap and leave it in place. Oxygen will diffuse through the holes and you'll be rewarded with beautiful smelling compost for the garden. If you haven't got enough room for a cold compost heap, then just bury kitchen scraps in the soil and cover them over to let the earthworms do the work. Whether you use this or the cold compost method, either way you'll be creating a great tonic for the soil and your garden will love you forever.
