An alternative way to compost is to create a worm farm. A worm farm is an area set aside in your garden populated by specially bred worms that munch their way through your household waste and turn it into high quality natural fertiliser.
- First, you need a worm farm. North Sydney residents who complete a Compost Revolution tutorial and pass the quiz will qualify for a worm farm and/or compost bin at a 50% discount. If you prefer a different type and are happy to pay a bit more, they are available from any good hardware store or nursery.
- Alternatively, make your own - ask your greengrocer or supermarket for two foam boxes. Make holes in the bottom of one box and place it over the top of the other to allow liquid to drain out into the second box. Make a bed of compost, torn up newspapers and leaves that's between 10cms and 15cms thick. Soak it in water before placing in the uppermost box.
- Now add the worms. You'll need around 1000-2000 (depending on the size of your box). Red worms or tiger worms are ideal and can be bought from nurseries, most hardware stores and garden centres.
- Begin adding food scraps to the bedding, but in small amounts. Over time as the worms begin to breed you can increase the amount.
- Cover the bedding and food scraps with hessian or layers of newspaper.
- Add water to the bedding whenever it becomes dry - it should be the consistency of a lightly squeezed sponge. Don't overwater or the worms will die.
- Place the worm farm in a shady spot in the garden. Worms don't like too much heat or direct sunlight.
- Harvest the worm castings by moving it to one side of the box and then removing. Add fresh bedding and food scraps to the empty area. Repeat the process as needed.
Do's and don'ts of worm farming
Do use food wastes such as vegetable peelings, fruit pulp from the juicer, fruit peelings (but not citrus), tea bags, crushed egg shells, bread, small amounts of shredded newspaper or cardboard, leftover cooked food such as pasta.
Don't use dairy products (or only in very small amounts), meat fat and bones, fish, citrus peels such as lemon or orange, cooking oil, onion and garlic.
Common worm farm problems
Your worm farm is too wet or you're overfeeding the worms. Reduce the amount of food and watering.
Worms aren't generally bothered by other insects but to avoid cockroaches, keep the worm farm covered at all times and place a tray of water underneath to discourage visitors.
Worms won't breed unless the temperature is between 18 and 25ºC. Feeding them too much citrus based food discourages them from breeding too.
Using your worm castings
- The worm castings are known as vermi-compost and can be harvested very few days.
- Take a trowel and gently remove them from the box. Store in a container in a cool dry place.
- Worm castings can be mixed with other compost before using.
- Use as a starting mix for vegetable and flower seeds by mixing one third sand with two thirds vermi-compost. This mixture should have a fine texture.
- Vermi-compost can also be used when planting seedlings by digging into a newly turned garden bed.
- For indoor potted plants, mix sand with the vermi-compost to encourage good drainage.
- Try and keep the liquid draining out of the bottom of the worm farm. It's full of nutrients and is an ideal pick-me-up for indoor plants.