Compost bins

Everyone thinks they know about traditional home composting, but it can be a little different to what you've always thought. Read on to find out how to create a healthy, usable compost at your place.

Getting started

Choose a sunny spot to place your compost bin. Position directly on the earth so soil life can enter. Layer twigs at the base so air can flow freely inside.

Compost recipe

It's important to get the balance of greens and browns right. When you add food waste/Bokashi solids or lawn clippings to your compost, try to alternate with browns/dry materials. Otherwise your compost pile may go anaerobic, and become a smelly sludge. Think of your compost as a sandwich, where browns are the bread and greens are the filling.

Feeding your compost

Keep feeding your compost 30 percent greens and 70 percent browns. This will help build up heat to speed up the composting. Compost should be moist like a sponge; add water to the dry material, cover to trap moisture, and make sure there is plenty of air flow. Turning your compost will speed up the composting process, but isn’t essential.

What to add

30% greens: anything soft, fresh, and nitrogen rich:

chopped fruit and veggie scraps
egg shells
cooked veggie leftoves
coffee grounds, tea leaves and tea bags
fresh garden waste
fresh grass clippings.

70% browns: anything brown, brittle and carbon rich:

small twigs
dried brown grass clippings
cardboard and certified home compostable packaging
paper towels
dry leaves and garden waste
indoor cut flowers.

What not to add

Noxious weeds, dog and cat faeces (manure from grass-eating animals is fine), oil and other liquids, cooked and/or processed foods (eg, bread, pasta and meat – unless it has been treated with Bokashi first).

Harvest time

Compost is ready to harvest when it becomes dark and crumbly and you cannot identify the original materials in it. This normally takes 6–9 months. Harvest the bottom third of composted material by removing the bin. With a garden fork, take the top two-thirds of semi-composted material and place it back in the bin. This will leave a pile of good quality compost to spread over your garden.

Your health and safety

Compost can contain micro-organisms such as Legionella, which can cause serious illness. We advise you wear a face mask and/or avoid breathing in vapour if the compost is steaming. Always wear gloves when handling compost, and wash your hands afterwards.

Troubleshooting

Some common composting problems, and how to fix them.

Problem	Solution
Not breaking down	Your compost is probably too dry. Mix it with a garden fork while adding water.
Smelly or slimy	Your compost is either too wet, lacking browns, or needs air. Mix it up and add some browns (scrunched up newspaper or torn cardboard work well). Add a sprinkle of garden lime.
Flies	Don’t add meat scraps or cooked food. Cover food with a thick layer of browns.
Rodents	Don’t add meat, cooked or processed foods. Make sure your compost is hot by adding the right balance of browns and greens, water and air. If rodents persist you can rat-proof your bin: place your compost bin on a base of fine wire netting that extends 10cm beyond its edge bend the netting up around your compost bin and tie on with cable ties push the wire netting into the air holes as a barrier, which still allows for air circulation. OR stop adding food waste to your compost bin – use a Bokashi bin or worm farm instead (adding food waste that has been “pickled” by bokashi is fine).