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Worm farming is a way to get rid of food organic waste, obtaining liquid fertiliser in its place. Foods scraps are placed in a worm farm regularly and special worm breeds eat their way through the food waste creating the liquid fertiliser that can be used on your vegetable or flower gardens to improve the health of the soil. It is important to buy the correct worms for a worm farm as they are not the same worms that you will find in garden soil. Worms are little more than intestines surrounded by muscles which breathe through their skin. Plant material goes in the mouth and waste emerges from the tail as worm tea and worm castings while the worms thrive well in decomposing food matter.

Reasons to grow a worm farm are:

  • waste reduction
  • making a balanced organic fertiliser
  • little maintenance other than turning the compost and harvesting the castings
  • can be kept anywhere, except in the light
  • does not smell if the food supply is constant.


Worm farming is also called vermicomposting and the growing of worms for this process is called vermiculture. The end products of worm farming to be harvested are worm tea (liquid fertiliser) and worm castings (a rich plant food also known as vermicast – worm castings, worm poo, worm humus, worm manure or worm faeces – all of these mean the same). In many countries, vermicomposting is used in the treatment of sewage. Composting worms are known as ‘tigers’, ‘reds’ and ‘blues’ and can be purchased, usually in lots of 1000 or less, from garden centres or hardware stores. Baby worms take about three months to mature and mature worms can be identified by a ring-shaped swelling around their body. Worms multiply quickly and to start you will need about 1000 to deal with about 500gms of waste per day.

Avoid feeding the worms with onion, garlic, chilli, dairy, citrus fruit (lemons, limes or oranges), meat and bones, fish, oils or grease, dog or cat faeces. Foods that can be used are fruit and vegetable scraps, teabags and coffee grounds, crushed eggshells, small amounts of bread or pasta, moist cardboard and newspaper. Smaller pieces of food will break down faster, thus speeding up the composting process. Banana peels are good but cut them into small pieces first. Make sure that food is at room temperature before adding it to your worm bin. Some processed food contains preservatives, which discourage the worms from eating it. These foods will not harm your worms, but they will break down and rot in the bin. Make sure that worms are actively engaged in eating the food you added most recently in the top feeding tray before adding more food. If they are not, this is a sign of overfeeding.


What to feed worms in a worm farm:

Always try to add equal portions of Greens (vegetable and fruit scraps, bread, pasta, coffee grounds and filters, teabags egg shells, grass clippings and dead plant matter from houseplants) and Browns (paper, paper egg cartons, cardboard and dry leaves).

Greens are high in organic nitrogen sources. These products help the worms to grow and breed, thus creating hot internal temperatures in compost piles. Browns are high in organic carbon sources which supply the energy that soil organisms need to survive. Carbons also help to absorb the offensive odours and prevent most of the organic nitrogen in the piles from escaping by evaporation or leaching. Carbons are also necessary in the formation of castings. A simple test to determine if your organic matter is green or brown, is to wet it and wait a few days. If it stinks, it is green; if not, it is brown.


How to start a worm farm:

  1. Decide the Location – location is so important when raising worms. The whole operation takes up about three square feet of space that has a steady temperature between 40-80⁰F and is not in direct sunlight otherwise the worms will be cooked! Place the farm in a protected shady place, out of the rain. A basement is ideal or a corner in a house, maybe under a table.
  2. Building the worm farm by purchasing a compost bin or make your own using old dresser drawer or wooden boxes or plastic boxes with holes drilled on the bottom so the moisture will drain out. Stack the boxes in a way that the fluids can drain easily otherwise the worms can drown. You can use small pots upside down to keep the layers separated.
  3. Create the compost bedding using shredded newspaper or cardboard, leaves, garden cuttings and a few scoops of soil which helps to process the food. Fill the bin up about ¾ of the way but keep it fluffy and airy so the air can circulate properly.
  4. Purchase the special worms from a nursery or hardware store. After placing the worms in the top box, place some moist newspaper over them for protection and to prevent them from crawling out of the box. Leave for a week without food as they need to burrow down into the compost mixture.
  5. Feed the worms – for every 500gm of worms you will need 250gm of food. Use both green and brown ingredients but if you have a day or two without a supply of food scraps, then shred some old newspaper and add it to the top layer. You do not need to spread the food – the worms will do this themselves. They do need to be fed at least every second day.
  6. Monetise your worm farm – when the worms are producing liquid fertiliser and castings, then you can sell these by advertising in your local newspaper or shop window or at a local farmers’ market or you can set up a roadside stall.
  7. When you are building the farm, remember that the bottom layer, in which the liquid fertiliser will be collected, must have a waterproof layer on the bottom for the collection of the liquid. The upper layers all need holes in the base for the liquid to run through into the bottom layer. If possible, install a tap on the bottom layer to drain the liquid off easily. In dry weather keep the bedding damp by adding a little water so that it does not dry out



  • Start-up Capital: $50
  • Space required: Enough space for the worm farm
  • Equipment:  Worm farm structure, small spade and gloves
  • Specific skills: Ability to harvest the fertilizer


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