Composting

Compost is a mixture of organic material that is used as fertiliser. Generally, the ingredients used to make compost come from our gardens and kitchens (food scraps), although organic material is anything that was once living.

As the organic material breaks down, it changes and becomes what is known as humus. During the process, soil micro-organisms, worms and insects convert the organics into a soil-like material that can then be used in the garden.

The benefits of composting are:

• It returns organic matter to the soil.
• It reduces the harmful effects of organic waste in landfill (e.g. water pollution, emissions of the potent greenhouse gas methane and bad smells).
• It reduces the need for chemical fertilisers in your garden.
• It reduces rubbish collection costs.
• It reduces the space needed for landfills.

Mitre10 has a guide on how to make your own compost, with information on what can and can’t go into compost, as well as common problems.

Types of compost bins

Before you choose a compost bin, you should consider what you will be putting in it. Larger open bins are better for people with large amounts of garden waste. Smaller enclosed bins are more suitable for households with large quantities of food waste because they provide a barrier to rodents.

If you are making your own compost bin, you can use a range of materials, including chicken wire, wood, plywood, bricks and concrete blocks.

Stacking bins have the advantage of being moveable and can be extended to cope with large amounts of waste. Black polythene or sacks may be used for lining, warmth and moisture control. Wrap a netting frame around wooden stakes and line it with newspaper or cardboard to retain the heat.

Things you need to know to get started

What makes my compost smell?
A compost high in nitrogen with no air will become acidic. Add carbon and turn your compost to reduce the smell.

How do I keep rodents out?
Add grass clippings to your compost to increase the heat and turn it regularly.

What can I not put in a compost bin? How long do I have to wait until my compost is ready?
A well-maintained compost bin will produce compost in three-to-four months in summer, and up to six months in winter. These times may vary depending on the method, bin contents, time of year and regularity of turning.

How will compost help my garden? 
Compost feeds the soil, helps with water retention and encourages earthworms into your garden.