The Basics of Composting
What do I do first?
First, choose a shady spot in the garden for your compost bin, enclosure or heap. Too much sun will dry out your compost. Then set up a separate bin in the kitchen for food scraps. To make good compost quickly, your compost needs food, air and water.
Feed your compost with a mix of 'greens' and 'browns'.
‘Greens’ consist of fresh plant material such as green weeds, fruit and vegetable scraps, green leaves, coffee grounds, tea bags, blood and bone and fresh horse manure.
‘Browns’ consist of dry materials such as straw, dry brown seedless weeds, autumn leaves, ash, dolomite, woodchips and sawdust.
Add the greens, browns and shredded paper to the heap in layers. As the billions of microbes multiply and digest the organic waste, they produce heat.
Layering your food scraps keeps the mix aerated and build heat which speeds up the process
Don't put the following in your compost bin:
- Droppings from cats or dogs;
- Bread or cakes as they attract mice;
- Diseased plants;
- Meat and dairy products;
- Metals, plastics, glass.
Make sure that your pile has enough air by:
- Breaking up clumps of food waste;
- Putting twigs and newspaper in the mix to increase airspaces;
- Adding some compost worms.
Compost can be made without air (anaerobically), but decomposition is slow, the pile will smell and it will produce methane, a powerful greenhouse gas. When the pile has enough air, the microbes that decompose the material thrive and produce better, less smelly compost more quickly.
All living creatures need water, even microbes, so keep your compost as moist as a wet sponge. A dry pile makes composting too slow. However, if the pile is too wet, the ingredients become heavy and exclude air from the pile, slowing the composting process and creating bad smells.
Using Your Compost
After 4 months or so, when the compost is dark and crumbly, it will be ready to use. Dig it into your garden beds or spread it on top of an established garden as mulch. Always wear gloves when working with compost and take necessary health precautions.
Compost Containers and Heaps
There are many types of home composting containers, including:
- plastic bins with ventilation holes or slits;
- plastic bins without ventilation;
- metal drums with holes punched in the side and with the base removed;
- rotating drum units (tumblers);
- enclosures made from timber (planks or sleepers), bricks, or chicken wire.
If you prefer, you can also make compost in open heaps, but they should be covered with either a plastic sheet or some hessian to prevent the heap from drying out in hot weather.
Health Precautions with Compost
Compost is produced from natural materials and contains a variety of living organisms. On rare occasions, these organisms have been associated with illness and allergies in humans.
For health reasons, it is very important to take the following health precautions when handling compost:
- Wash your hands after handling compost or soil materials;
- Protect broken skin by wearing gloves;
- Avoid confined spaces for handling compost or soil materials;
- Keep compost moist to prevent spores or bacteria from becoming airborne;
- Gently moisten dry compost to allow dust-free handling. Avoid inhalation of dry compost.
For individuals who have allergies to the fungal spores in compost or depressed immune systems, it may be necessary to wear a face mask when working with dry compost. Severely affected individuals may have to avoid contact with compost altogether. Elderly gardeners should be especially careful when working with compost.