What is Compost?
Quite simply it 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 which can then be used in the garden.
The benefits of Compost
- 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.
How to get started
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.
Create Your Own Eden, an initiative of the Auckland, Nelson and Invercargill City Councils, has a comprehensive guide to making your own compost.
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 as they provide a barrier to rodents.
Make your own compost bin
If you are making your own bin, you can use a wide range of material, including chicken wire, wood, plywood, bricks, concrete blocks, etc.
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. Line these with newspaper or cardboard to retain heat.
Frequently Asked Questions About Composting
- What makes my compost smell?
A compost high in nitrogen with no air will become acidic. Add carbon and turn your compost.
- How do I keep rodents out?
Add grass clippings to increase heat and turn regularly.
- What can I not put in a compost bin?
See here for a list of what not to compost- http://www.createyourowneden.org.nz/comp_whatnotto.html
- How long do I have to wait until my compost is ready?
A well maintained compost bin will produce compost in 3-4 months in summer, and up to 6 months in winter. However, times 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.
What is Bokashi?
If you don’t have enough space for a compost bin then Bokashi offers an alternative to composting.
Bokashi was developed in Japan and literally means ‘fermented organic matter’.
A fermented wheat- bran mixture called Compost-Zing is used in a bucket system where food is literally pickled. The final product has a slight sweet/sour smell.
One of the benefits of Bokashi is that it has no odour so can be placed inside. This means that you can add products such as meat and fish, which are discouraged in the usual compost due to vermin & odours.
Not only is it easy to use, readily available, and environmentally friendly, it also gives you many advantages over regular composting:
- up to 50% quicker composting time
- less odour as the food decays
- healthier and more productive plants
- requires no mixing
- produces a natural pour-on liquid fertiliser as well as physical compost.
Bokashi.co.nz has all the information and products to help you get started.