Composting

How Composting works

About half the household waste in Australia is made up of food and garden waste. Most of this material could be composted to save landfill, improve soil condition and provide fertiliser in the garden at no cost.

Composting is the method of breaking down waste organic materials in a large container or heap. The decomposition occurs because of the naturally occurring micro-organisms, such as bacteria and fungi.

Best composting conditions

  • The correct ratio of carbon to nitrogen (roughly equal amounts of browns and greens)
  • The correct amount of water (feels like a damp sponge)
  • Sufficient oxygen (turned with a fork often)

In these conditions, bacteria and fungi feed and multiply, giving off a great deal of heat. In well managed heaps, the temperature can reach up to 60ºC, which is sufficient to kill weed seeds and organisms that cause disease in plants and animals. When the temperature drops, invertebrates enter the heap from surrounding soil and complete the process of decomposition.

Where to get bins

Composting bins can be purchased from most hardware stores. Look in the Yellow Pages.

What can and can't go into a compost bin

Can go in Compost
Can't go in Compost
Vegetable and fruit scraps
Meat and Dairy products
Fallen Leaves
Diseased Plants
Tea Leaves and Tea Bags
Metals, plastic & glass
Coffee Grounds
Droppings of meat eating animals (eg dogs)
Vacuum Cleaner Dust
Fats or Oils
Soft Stems
Magazines
Dead Flowers
Large Branches
Used Vegetable Cooking Oil
Weeds that have seeds or underground stems
Egg Shells
Bread or cake (attracts mice)
Lawn Clippings
Bones
Old Newspapers

Sawdust (not from treated timber)

Compost troubleshooting

Problem
Cause
Solution
Rats or Mice
Attracted by uncovered food and or warmth of heap
Cover each additional of food with a layer of soil. Place the bin on a layer of fine wire mesh. Set traps around the bin.
A lot of slaters or ants
Heap is too dry
Add water or some moist organic materials.
Spiders under the lid
Attracted by invertebrates, most likely small flies.
Have a handle on the top of the lid. Wear Gloves. Cover each addition of food with a layer of soil.
Compost takes too long to break down
Too Dry.
Not right mix of greens and browns. Not enough Air.
Add Water. Add equal amounts of greens and browns.
Turn more frequently. Add worms. Punch holes in container. Place length of slotted pipe in the heap.
Smelly
Too Wet.
Too Acidic
Insufficient Air
Add some wood ash or dolomite to neutralise the heap.
Turn more often.
Rebuild with some dry materials.
Flies
Most of the flies in and around a compost heap are small vinegar flies, which are quite harmless. If the flies are houseflies or blowflies, then they are being attracted by meat, dairy foods or manure.
Cover organic waste with a thin layer of soil, grass or leaves.
Avoid adding meat, dairy foods or manure