Create your own worm farm

A worm farm turns organic waste such as kitchen scraps into fertiliser for your garden.

Feeding fruit and vegetable scraps to composting worms is a cheap and simple way of recycling food and garden waste. Worm castings make a great fertiliser for gardens.

Worm farms are ideal for people living in flats or houses with small backyards and for dealing with lunch scraps at the office. They don’t take up much room and can be placed on a balcony - all you need is a small, cool, well-shaded spot.

Worm farms can be bought from most hardware or gardening shops. It’s also easy to make your own worm farm out of old containers, bins, tyres or old fridges.

• How to set up your worm farm
• What to feed the worms
• What not to feed them
• How to keep your worms happy
• Useful facts
• Ideal conditions
• Reduce your ecological footprint
• Where to buy worms
• How to make your own worm farm
• Worm farm problems and solutions

How to set up your worm farm

One style of ready-made worm farm housing, which is normally available from local hardware stores and nurseries, comes as a stack of two, three or four trays. The lowest tray is a drip tray (collector tray), which is then topped with the worms bedding tray and/or feeding tray (working trays).

Some hardware stores and nurseries also sell the live compost worms to go in the farm housing. They can also be purchased separately from any local worm farmer who breeds and sells compost worms.

What to feed the worms

Worms are great eaters and like most vegetable and fruit scraps, except for onions and citrus. Because worms do not have teeth, scraps should be cut into small pieces.

Favourite foods include: watermelon, apple, avocado, pear, grapes, carrot, cabbage, mushroom, pumpkin and many other kinds of vegetable and fruit scraps.

Worms also like: soaked and ripped pizza boxes, shredded and soaked cardboard, newspaper, teabags, coffee grinds, egg shells, leaves, and hair.

What not to feed them

Don’t try to feed worms food such as meat, cheese, jam, butter, biscuits, cake or any other highly processed food. They’ll refuse to eat it, causing the food to spoil and create unpleasant odours in the worm farm.

They also don’t like onions, shallots, garlic or too much acidic food like oranges, mandarins or pineapples.

No meat and dairy products should be added to a worm farm.

How to keep your worms happy

Your worms will be happy as long as you follow a few simple rules:

• Keep the worm farm out of extremes of weather, i.e. out of the sun and rain
• Keep the worm farm damp but not wet. Water every so often or as required
• Give them a range of different foods to keep them interested
• Try not to feed your worms too much or the wrong types of food 
• feed your worms too much or the wrong types of food
• Keep the worm farm clean and hygienic, and it shouldn’t have any unpleasant odours unless they are fed too much or the wrong types of food
• When going on holiday, an established worm farm can be left for 3-4 weeks by making sure it has enough food to last that time. Fresh compost, shredded newspaper or cardboard works well. Make sure it is moist before you leave and is in a protected area.

Useful facts

• Compost worms such as Tiger Worms, Red Wrigglers and Indian Blues love the rich moist conditions of a wormery. Ordinary earthworms can’t survive the rich conditions.
• Worms only breed if there is enough food. In good conditions, the population can double in 2-3 months.
• Compost worms breed every 7-10 days, but when the worm farm reaches capacity, the breeding stops.
• The worms in a small worm farm should eat all the fruit and vegetable waste produced by a household of four.
• Worm castings and the liquid fertiliser are useful additives to any garden bed, as they are organic and have a neutral pH of 7.
  • The castings and liquid fertiliser provide an excellent fertiliser and can be used on all plants.
  • The liquid fertiliser can be used when diluted with water (1 part worm juice to 10 parts water) and the castings spread around the drip line of plants and trees.

Ideal conditions

Worms will tolerate a temperature range from approximately 10-30 degrees celsius. If it gets much hotter than this, move the system into a shady, cool position. In very cold temperatures, cover the system with some old carpet, blankets, or hessian to keep warmth in.

Feed the worms more, it will create some warmth as the food decomposes.

Compost worms require moist conditions all year round, and do not tunnel deep to find moisture. They can only be useful in the garden if you have a thick layer of mulch in your garden.

You can never have too many worms. Worms self-regulate their population according to available space and the amount of food you give them.

Reduce your ecological footprint

Keeping a worm farm helps to reduce your ecological footprint as you reduce your organic waste from going in to landfill.

Approximately 77% of household waste going into landfill could be diverted. Composting and worm farming can remove over 50% and learning to recycle right can reduce it by another 19%.

Where to buy worms

Worms can be bought direct from commercial worm growers or through your local nursery.

They are generally sold by the thousand – 1,000 worms weigh about 250 grams.

How to make your own worm farm

 

Step 1: Choose a nice spot for your worms to live

Make sure the spot is not too hot or cold.

Step 2: Get two boxes

Old containers work well. They need to stack one of top of the other well.

Step 3: Make drainage holes

Make small holes in the bottom of one box to let liquid drain and place the box with the holes on top of the other box without holes.

Step 4: Make a tap

Make a tap in the bottom box to let the liquid drain out. Do this by poking a length of hose through one end of the box. Turn the hose upwards to turn the tap off.

Step 5: Make the bedding

Tear up some leaves, newspaper and cardboard to make a layer of bedding about 15-25cm deep. Compost or cow manure can also be used. Soak the bedding before it is added to the box.

Step 6: Add the worms

Add about 1,000 worms to the top of your worm farm. Spread the worms out gently on the surface and allow them to burrow down.

Step 7: Add food waste

Put your kitchen waste on top of the bedding regularly but in small amounts. Over time, as more worms breed, you will be able to give them more to eat.

Some things to remember:

• Don't add too much at once
• Do not feed worms meat, bones, fatty food or dairy products
• Worms may not eat raw potato – but they do eat cooked potato
• Worms don't like oranges, grapefruit and lemons, or raw onions or raw garlic
• Some food waste such as fruit, grains and sugary foods form acid. Adding a little wood ash,  dolomite or lime every few weeks will prevent the worm farm from becoming too acidic. Open the lid and wait until the worms burrow under. When you can't see them anymore, apply the lime or wood ash.

Step 8: Cover the worm bed

Cover the worm bed with newspaper or a piece of hessian. If you are able to get a lid with the containers, put this on too. This will help keep a constant temperature in the worm farm.

Add water to the box whenever it begins to get dry. It should be the consistency of a lightly squeezed sponge; if it is too wet the worms will die.

The worm farms should be placed in a shady spot in your garden or garage.

Step 9: Harvest the worm castings

Harvest the worm castings by moving it all to one side of the bin. Add fresh bedding to the empty side. Many of the worms will move to the fresh bedding in a few days. The valuable worm castings can then be taken out and used to feed plants, add to seedling mixes and potting soils.

In addition, the liquid which is called 'worm tea' that collects in the base or bottom container can be used as a liquid fertiliser, once it has been diluted. It should be diluted at about 1 part worm tea to 10 parts water. As your plants get used to the solution the strength can be increased.

Worm farm problems and solutions

 

Problem	Cause and solutions
My worm farm smells	Giving worms too much food or farm is too wet: Stop feeding the worms, add some garden lime and stir the top tray lightly to aerate the mixture. This will allow the worms to move through it more easily. Start feeding again when all smells are gone.
Flies around farm	Feeding worms too much or too moist: Sometimes small vinegar flies get into the system, however they will not do any harm. If larger flies are present slow your rate of feeding, or if too moist let it dry a little.
Unwelcome visitors? Ants and cockroaches	Too dry: Add some water to raise the moisture levels. Always keep a lid on the farm and keep a hessian/cardboard cover over the food scraps. Keep a lid on the farm or keep a hessian cover over the food scraps. To stop unwelcome visitors from getting into the farm, place the legs of it in a container of water or rub Vaseline on the legs.
It's raining and the worms are gathering in the lid?	Weather is changing: Worms move up into the lid before it rains to avoid drowning. Move the system out of the rain and replace the worms in the bedding
Maggots	Meat scraps: Avoid meat in your worm farm. To remove maggots place bread soaked in milk on the surface. The maggots will be attracted to it and you can remove them after a couple of days.
Worms leave	Don’t like food or soil that’s been added: If worms are not happy with their food or bedding they may climb out of the worm farm. Place another tray with a fresh food supply and some compost on top of the contaminated tray.Once the worms have climbed out of the contaminated tray (about a week) remove the offending food or soil, and use the castings in the garden. Never add soil or dirt as bedding. Only compost, manure or damp coir should be used as worm farm bedding.