Worm farming is a great idea for getting rid of kitchen scraps. Plus creates a natural (and low cost) fertiliser and gives the kids a low maintenance project they can own. Worms turn food scraps into a soil amendment called vermicastings, also known as worm castings or worm poo, which speeds up plant growth and reduces the effect of plant diseases and pests.
It can be used as mulch or added to potting mix. The other by-product of worm farms is vermiliquid or worm tea (named for its colour), the liquid is mostly produced by decomposing waste before the worms process it. Worm tea can be diluted and used as a liquid fertiliser.
If you consider yourself a squeamish person, you shouldn`t be put off having a worm farm as they don`t need to be handled, in fact, when you lift the lid off to feed them, they vanish from sight to avoid light. Worm farming involves very little work and can be an indoor or outdoor set-up.
You can make your own worm farm cheaply and easily out of wood or plastic storage containers. Here’s how:
Your worm farm needs to be in a cool shady location e.g. a shaded area on a balcony, a carport or garage or under a tree. Some people have their worm farms in their kitchen, as they don’t produce nasty smells when working correctly.
Depending on the size of your worm farm you will need 250g – 1kg (approx. 1000 – 2000 worms) of composting worms. You can find these in the garden department at our Mitre 10 MEGA stores - you must use composting worms (usually called tiger worms in New Zealand).
Soak the bedding materials in a bucket of water for 10 minutes. Suitable bedding can be a mixture of:
Loosely wring out the bedding and fluff it before placing it in the worm bin. Fill bin about half full (at least 10cm) of moist bedding and mix through a handful of soil, then add your worms.
Place a blanket that has been cut to size on top of the bedding to keep everything moist and dark. This could be a worm farm blanket, old blanket, sack cloth or scrap of wool carpet, then replace the lid and let the worms settle in for a few days before their first feed.
Worms are happiest between 10-30°C. You may need to shift your worm farm into a shed or basement if your area has cold winters, and keep shaded and cooler during hotter months. You can insulate the worm bin with blankets, straw, old duvets or other material to keep it warm. Make sure that the worms have at least 10cm of bedding.
You can sprinkle lime, wood ash or dolomite on your worm farm every few weeks, or use a specific worm farm conditioner. Avoid acidic composting foods e.g. citrus peel.
Your worm farm should always feel like a damp sponge. If it is too dry, spray some water on each layer. If your worm farm collects rain, your worms could drown. Move it into a more sheltered position, cover the holes or replace the lid with something more suitable and add shredded newspaper to absorb the excess water.
Allow your worms a few days to settle into their new home then add a handful of food scraps to the surface area. Cover the food with 5cm of bedding. Wait until the food scraps are eaten before adding more. It will take a while before the worm farm is processing scraps at its full rate, so start slowly.
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After three to six months, the worms will have created enough castings for harvest in the bottom of the worm bin. There are two easy ways to collect this:
Worm farms generally have a tap so you can collect the worm tea in your watering can as it is produced. If you don’t have a tap, just check the collection tray regularly and tip the liquid into a container.
Castings can be used immediately or stored for later use. It can be used as mulch, mixed straight into the soil, or added to other ingredients to make a potting mix.
Dilute 10:1, (it should resemble weak tea) and use as a liquid fertiliser or foliar spray on most plants.
Worms have small mouths. The more surface area the better, therefore putting food scraps into a blender or food processor will help them eat.
The presence of small white worms can mean the worm bin is too acidic, so add some lime. If there are lots of white worms, cover food with damp paper and add lime or worm farm conditioner to change the PH
Worms can tolerate temperatures ranging from 10-30°C. In summer, shade is necessary, however sun can be helpful in winter. Place your worm farm under a deciduous tree or move it seasonally. Use old blankets or duvets during frosts. If the temperature drops below 10°, you can move the worm farm into a basement or shed. You could also increase the amount of food that you give them, as this will create some warmth as it decomposes (watch for signs of over feeding).
If you get little black fruit flies, cover the worms with an old damp tea towel, soaked newspaper, worm blanket or hessian sack. Excessive numbers of fruit fries are a sign of over feeding. Check that your worm farm is vermin-proof (rats and mice). Add more lime, add more paper, dried leaves.
Worm farms should produce a `rainforest` smell. Unpleasant odours indicate that bacteria levels have built up from uneaten food. Stop feeding them for a few days and stir the food scraps through.
Worm farms should self- regulate their population at 12 months. If you put composting worms into your garden, they will die from starvation and dehydration. If you have a thick layer of mulch they may survive as they need moist conditions. If you have excess composting worms, give them to another gardener.
Worms will crawl up the sides, look fat and pale. Add paper products, dry leaves, aerate the layers by poking with a fork.
