Composting and worm farming

Recycling Community

Did you know? About half (50%) of what we throw into the general waste bin is food and garden waste! Instead, many of these materials can be treated and used in your garden at home.


Composting is a natural process that breaks down food and garden waste into rich organic material and soil conditioners.

Bacteria and organisms breakdown this waste and therefore need sun, air, moisture, a mixture of dry and wet garden / kitchen waste, and to be placed directly on the ground or in a garden.

You can purchase a compost bin or you can make your own out of reusable or recyclable materials. Most commercial models come complete with a lid, but if yours doesn't or you have built a compost bay or star picket and chicken wire model, you can use homemade compost covers.

Compost covers

  • Wet newspaper
  • Old carpet / underlay
  • Tin or roofing materials
  • Or anything that slows water loss, allows some air flow and limits access by vermin

For more information on how to set up and maintain a composting system, refer to the Easy composting fact sheet.

Worm farming

Worm farming is the use of specialised compost worms to break down food waste into rich solid and liquid soil conditioners.

As the worms live off the household scraps, they generate liquid and worm castings which are nutrient rich, water holding plant food. This liquid fertiliser and soil conditioner can be added to your garden soil, as well as your potted plants.

You can purchase a worm farm or make one yourself from reusable items (eg. use old laundry or bath tub) and capture the worm liquid by attaching some flexible hose from the drainage outlet to a bucket.

You can also stack polystyrene boxes so the top layer has drainage holes in the base and the bottom layer captures the worm liquid. You need a lid or covering for the worm farm to minimise flying and crawling pests, plus maintain moisture. See, compost covers.

Composting worms can be purchased online or from some hardware stores and larger garden centres. Try the Yellow Pages under 'composting worms'. They are special worms that eat organic matter, and they are not earthworms.

How many worms do I need? The number of composting worms you need depend upon your food waste disposal quantity. Generally 1,000 worms will be adequate for 1-2 persons and 2,000 worms for 3-4 persons. The worms will multiply if they are kept moist, cool and have plenty of vegetable and fruit scraps to eat.

Feeding your composting worms - the smaller the pieces of food scraps, the quicker the worms can process the waste. You may prefer to blend / process food into small pieces, or soften the food in the microwave to assist the worms to eat through the larger/tougher vegetable scraps. Worms are happy to process larger pieces of food if they need to, but bury the food in the worm castings to make it more palatable for the worms and reduce the flying pests.

Things you should never feed composting worms:

  • Acidic citrus
  • Onions
  • Meat
  • Recently wormed pet faeces

For more information on how to set up and maintain a worm farming system, refer to the easy worm farming fact sheet.

Where does garden / food waste go if put in general waste bin?

The organic lawn clippings, prunings from your garden and peelings/food waste from your kitchen if placed in your household general waste bin, end up in the landfill.

Buried in landfill these valuable organic materials can contribute to environmental problems such as the production of greenhouse gases including methane and carbon dioxide emissions, and the increased potential for water pollution.

By turning your food and garden waste into compost / mulch, you can make a difference to our environment and reap the benefits by:

  • Reducing the amount of waste you dispose
  • Reducing the use of artificial fertilisers
  • Reduce the amount of water needed for your garden
  • Improving your local soil quality
  • Reduce the carbon emissions of buried organics in landfill
  • Creating a more natural healthier (and happier) place to live.

Composting methods

Your choice of which composting method suits you is determined by:

  1. Volume of kitchen / garden waste you produce at your home
  2. Access to outdoor space, with covered / shaded area and areas with ground access in full sun.

If large volumes of food and / or garden waste:

  • Composting bins / area for food and garden waste
  • Mulch garden waste and cover your gardens
  • Chickens will eat vegetable and fruit scraps and produce manure for the compost bin and gardens
  • Guinea pigs will eat some food scraps.

Food and/or small amount of garden prunings from a family or single person:

  • Compost bin for food and garden waste
  • Mulch garden waste and cover your gardens
  • Chickens and guinea pigs will eat vegetable and fruit scraps
  • Worm farm will convert your kitchen waste into worm castings and worm liquid. They can be stored on a unit balcony if there is plenty of shade
  • Bokashi composting system with fermented wheat as the activator. You will need multiple buckets as one will be resting, whilst the new one is being used. Perfect for units or homes with no or limited garden area.

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