Why should I compost?
Composting makes good environmental sense. It's cheaper than taking organic material and garden waste to landfills. Compost also provides an excellent material to enrich the garden and encourage plant growth.
Where should I keep my compost bin?
Composting can be done right in your own backyard in a sheltered area.
You’ll need:
- Good drainage
- Sheltered area
- A garden hose within reach
- A spot out of direct sunlight
The compost heap should sit directly on the soil.
How do I make compost?
The compost bin can be made at little cost. Your options for making the container:
- For an effective and flexible home-made container, wrap wire netting around wooden stakes and line with cardboard or newspaper
- Stronger bins can be made from wood, bricks, or concrete blocks. Holes for air and ready access from the front are necessary
- Alternatively, purchase a commercially-made bin from a garden centre or hardware store
Compost making - five simple steps:
- Before positioning the bin, fork over the soil to aid drainage and encourage worms. Ensure bin is aerated through ventilation openings or raise the bin on a few bricks
- Place a 10-15cm layer of coarse twiggy materials (materials from a previous heap may be used) at the bottom of the bin to ensure good drainage and entry of air
- Add a 15-20cm layer of moist, well mixed kitchen and garden wastes. Use a variety of organic material, and lightly compress with a fork. If materials are dry, lightly moisten
- Add a 5cm layer of poultry litter or animal manure. Seaweed, soil, or your own mature compost can be used if animal manure is not available. Alternatively, use a few handfuls of blood and bone, or sulphate of ammonia fertiliser, or a compost starter kit available from garden shops
- Continue to build the compost heap with alternating layers, as material becomes available. When the bin is full, cover and leave the heap to mature. If you regularly turn the compost heap it will take three to four months to mature, but without turning it will take nine months to a year. Turning once a month will aerate the heap and mix the decomposer organisms through the waste material
How do I use compost?
- When mature, spread three centimetres of compost and mix into topsoil. Any remaining stalky material can be removed and recycled into your next compost heap
- Mature compost mixed with two parts topsoil and one part sand makes an excellent seed-raising or potting mix
- Compost gives newly-planted trees and shrubs a good start. Mix one or two buckets of compost into the soil prior to planting
Then sit back and relax and watch your garden flourish, knowing that nature's recycling system is hard at work!
Composting tips
- Compost shouldn’t be too acidic. Try a light sprinkling of dolomite or lime every few layers
- To speed up the process, chop or shred materials into small pieces
- Aerate your compost regularly. Air is essential for odour-free composting
- Dampen your heap regularly in summer to maintain a consistency of a squeezed out sponge - moist but not soggy
- Compost is mature when it has darkened and has a crumbly soil-like material with a pleasant odour
- If offensive odours (such as "rotten eggs") are produced, turn your compost heap to aerate
- The best compost needs the right mix of carbon (dry stalks or leaves) and nitrogen (green matter, fruit or animal manure). Use four parts of carbon for each part of nitrogen material
- The volume of the compost heap needs to be large enough to insulate itself in order to maintain the heat of microbiological activity. A cubic metre or slightly larger is sufficient
Do's:
- Vegetable/fruit scraps or peelings
- Tea leaves
- Soft garden debris such as leaves, lawn clippings, weeds (if they have not gone to seed)
- Untreated wood ash, sawdust or straw
- Animal manures
- Seaweed
Don'ts:
- Meat, fish, fats or cooking/salad oils
- Wood, bones, tin, glass or plastic
- Diseased plant material
- Plant foliage with chemical sprays residue
- Weeds such as oxalis, live twitch, convolvulus, docks, dandelion
- Toxic material