Composting and Worm Farms

Composting and worm farming are useful and beneficial activities that can help minimise your impact on the environment by reducing the amount of organic waste being discarded to landfill. About two thirds of all household waste is suitable to be recycled in a compost bin or by a worm farm.

Composting 

What is composting?   

Composting is a method of speeding up and controlling the natural breakdown of organic matter into a soil-like substance for use as garden mulch and fertiliser.

Why use compost?    

• Save water - the water retention capacity of the soil is increased.
• Save on fertilisers and soil improvers - nutrients from compost are released into the soil slowly and are less likely to be lost by leaching than nutrients in soluble fertilisers.
• Reduce household waste  – kitchen scraps are suitable for composting. This in turn will extend the life of landfill sites and reduce problems caused by the leaching of organic matter in wetlands, rivers or the ocean.
• It will help make your garden the best fed in the street.

Are there any health risks from composting?    

A properly operated compost bin or tumbler poses little threat to your health. However, poorly operated compost bins may cause problems by encouraging the breeding of flies and vermin and may also produce bad smells.

By taking some simple precautions, risks to humans can be minimised:

• Use a fully enclosed compost bin or tumbler.
• Use gloves when handling compost.
• Keep compost moist, without soaking, to avoid dust.  

What to use

Grass clippings, kitchen waste, paper wrappings, fruit and vegetable peelings, prunings (shredded), tea leaves and tea bags, indoor plants, coffee grounds, eggshells, manure, weeds, vacuum cleaner dust, hair and wool, cardboard, sawdust. 
 

What not to use

Animal products (meat, fat, bones), plastic, large branches, waxy plant material, diseased plants, plant seeds, plant bulbs or runners, pesticide-contaminated plants, disposable nappies.  

Care and operation of your compost bin or tumbler: 

• Place your compost bin in a sunny location in your garden with the base open to the soil, to allow drainage and the entry of micro-organisms.
• Composting requires moisture – use a hose to moisten the materials being added to the compost bin. Too much moisture will create bad smells. Make sure the materials are damp to touch, but not enough moisture in it to be squeezed out. If you have ants, slaters and cockroaches in your compost bin, this indicates the materials are too dry.
• Your compost bin needs to be in a sunny position in your garden to allow for the heat in the bin to break down the materials. Temperatures in the compost bin can reach 60C, which helps to break down materials and kill bacteria.
• Make sure your compost bin lid is secure to prevent invasion by vermin.

Using the compost bin    

Correctly prepared compost has a pleasant earthy smell, has few recognisable pieces of the original organic material and is fairly uniform dark brown or black colour. It may be used as soon as the temperature has dropped below 40C, usually 3-4 weeks from starting.

The finished product can be dug into garden beds for vegetables or flowers, spread as mulch around shrubs and trees (keep 40-50cm away from the trunks of trees) or sieved as a top dressing for lawns.

Ensure compost is not too dry and dusty when it is spread. The dust from dry compost may cause allergy or respiratory symptoms and should be avoided.

Worm farms    

Feeding earthworms in a specifically designed worm farm is another good way to make high quality fertiliser from vegetable type food scraps, grass clippings and other organic matter.

There is no need to turn the material because the earthworms will automatically aerate it for you. Worm faming is an especially good idea for people who live in units or flats and only have a small courtyard or balcony.

Put pre-soaked bedding material such as compost and shredded paper to a depth of about 15- 20cm. Feed the worms anything organic (except citrus peel, onion, meat and dairy products), by placing it on top or burying it slightly in the bedding.