Building a compost heap
The essence of good composting is heat and air. To get a really hot compost heap it needs to be at least one cubic metre. You won’t achieve this with a standard shop bought bin. This means that your heap won’t reach temperatures high enough to kill the kind of pathogens produced by rotting meat so don’t put meat, or dairy products, in it.
The best compost heap has layers of kitchen waste interleaved with garden waste. Weeds that grow from bulbs and stalks such as oxalis, onion weed and wandering willie should not go into the compost heap.
If you have a pre-treatment bin you will be layering the partially decomposed kitchen scraps from it with the garden waste. Because the material from the pre-treatment bin is wet and has been deprived of air it will be smelly but once it is incorporated into the big heap, fast, aerobic decomposition will begin and the smell will go.
Turning the heap and extracting compost
After a few weeks, or longer, it is time to turn the heap. Lift the bin off and place it beside the compost. Then shovel the compost back into the bin fluffing it up as you go and mixing material from the top, middle, bottom and sides of the original heap. At this stage you can add additional layers of kitchen scraps or garden waste.
Organic waste breaks down faster when the air temperature is warm so it’s hard to say how long it will take before the compost is ready to use on your garden. Don’t wait too long though, compost doesn’t increase like savings in the bank, you need to use it promptly to get the most benefits. As soon as it becomes difficult to recognise what the compost was made of (apple cores, banana skins, cabbage leaves) it’s probably OK to pop it on the garden. You may have to sort out some woody items like corn cobs and pumpkin seeds for further time in the heap. As these take longer to decompose.
Links, contacts and further information
The Rodale book of composting highly recommended from a library near you
Want your waste composted but not at home? Take it to one of the special composting plants that run in conjunction with landfills in Wellington City, the Kapiti Coast and Masterton.
