At a glance
Worms eat organic waste and turn it into liquid fertiliser and worm castings (the organic material that has been digested by the worms). Both of these products can be used on your garden and on your pot plants to keep them thriving.
You can use worm liquid to replace fertiliser. The liquid needs to be diluted until it is the colour of weak tea. This mixture won't burn your plants. You could bottle your excess liquid and give it as a gift with instructions on how to use it.
Composting is another great way to reduce organic waste and improve soils.
Choose the type of worm farm
Get started by doing some research to work out what type of worm farm suits your needs and situation.
- A quick browse on the internet will turn up lots of useful resources including videos on how to build a worm farm. Talk to your local garden centre too. Also check your local council's website for worm farming guides, workshops, equipment and links to local suppliers.
- Work out where you will locate your farm. Worms don't like the heat or direct sun so choose a cool shady spot inside or outside.
- Choose the size of your farm. They can be as big or as small as you need, depending on how much organic waste you generate or how much space you have.
- You can look at the many types of ready-made farms—or it's easy to make your own farm out of recycled plastic, polystyrene vegetable boxes or wood (don't use treated wood as it can leach chemicals).
Prepare your worm farm for worms
- Your worms will need a bed inside their box. The bed should be made out of good-quality soil, leaves and shredded paper. The worm bed should be around 15 centimetres deep.
- Add a little water to the worm bed—it needs to be kept moist but not wet.
- Source your worms from commercial worm growers or your local nursery. The common types are: Tiger, Indian Blue and Red Wriggler. Worms are usually available by the thousand and you'll need between 1,000 and 2,000 worms to start with. They will multiply over time.
- Settle your worms in by gently spreading them over the surface and watch them burrow into their new bed. Remember to make sure your worms have enough bedding and that you keep your worm farm damp, covered and cool.
- If you notice pests like slugs and vinegar flies once your farm is up and running, dust the top with lime and check you haven't added too much food.
Feed your worms
- Worms are happy on a simple diet. They like food scraps including vegetable and fruit peelings, tea leaves, crushed eggshells and bread. They also like small amounts of moistened paper and cardboard such as shredded egg cartons.
- Chop up their food as small as possible so the worms will get through it faster.
- Add your kitchen waste regularly in small amounts and in one place at a time. Cover new food with a light cover of their bedding material or a handful of soil or compost.
- Only feed your worms when they have almost finished their last meal or it will start to rot.
- Don't feed worms on dairy (butter and cheese), meat, fish, fat or bones. They also don't like citrus peel, onion or garlic.
Harvest worm liquid and castings
- If your worm farm captures worm liquid, empty the tray regularly using the tap.
- To harvest the worm castings, move the worms' bedding to one side of the farm, add fresh bedding to the empty side; then wait a few days. Most of the worms will migrate over to the fresh bedding. Then you can take out the old bedding and use it on your garden.
- It's okay to transfer some worms into your garden when you empty the old bedding. You'll also be transferring worm eggs which will hatch in your garden and improve your soil.
- Use your castings to improve soil quality and for fertilising around plants. You can also add a sprinkle of worm castings onto pot plants.
- Dilute your liquid fertiliser. A good handful in a nine-litre bucket of water stirred really well can then be watered onto your plants.
- If you have a backyard, build a compost heap or bin to make use of the remainder of your food scraps as well as your garden waste—another simple way to make fertiliser and reduce the amount of waste going to landfill.