A compost bin can turn organic waste, including vegetable scraps and garden waste, into excellent quality compost which acts as a natural fertiliser to give the garden a boost. Organic material is confined in the compost bin where conditions can be controlled so that breakdown is accelerated and optimised. Micro-organisms, earthworms and insects in the soil assist in breaking down the organic waste in the compost bin.

Benefits of compost are:

  • Improves drainage
  • Assists plant growth and disease resistance
  • Absorbs and filters runoff
  • Reduces unwanted insects

Setting up your compost bin

Choose a position that is:

  • Well-drained and warm
  • Close to a water source

Layer your compost bin

  • Your compost bin needs layers of brown material which is high in the element carbon.
  • Alternate the brown layers with green materials which are high in the element nitrogen.
  • Sprinkle each layer with water.
  • Adding soil or compost adds micro-organisms to your bin.
  • These micro-organisms break down the organic matter into compost.
  • Aerate compost by turning over regularly.
  • Once the bin is full, do not add any more food scraps.
  • Add water, if necessary.
  • Your compost is ready when no food scraps are visible and the compost smells fresh and earthy, usually in 8-12 weeks. Turning the compost once a week speeds up the process.

    Compost bin diagram

Worm food

Compostable material includes food and vegetable scraps, hair, lawn and garden clippings, coffee grounds, tea bags, vacuum cleaner dust, straw and newspaper. 

Meat, bones and dairy products, metals, plastics and glass, magazines, large branches, bread and cakes should not be added to your compost bin. Also exclude animal manures (especially cat or dog droppings), weeds that have seeds, diseased plants and sawdust from treated timber.

Problem solving

1. Smelly compost caused from too much moisture, not enough air, too much/not enough food, or ‘other’ materials

  • Solution: stir in dry leaves, mulch or soil, turn the compost to get more air, add garden lime or dolomite, mix food with newspaper

2. Ants, cockroaches, flies, mice, rats

  • Solution: ensure food is covered by mulch, add lime and turn the compost, do not add meat to the compost

3. Too dry

  • Solution: add water