How to set up a small scale worm farm

Your Simple Gesture: Deep dive into how to set up a small scale worm farm

Not sure how you feel about living with squirmy worms who eat up your veg scraps? Well, when it comes to reducing your footprint and doing so with low maintenance, worms are your new best friends.

In searching for your first composting method, you may be wondering which is right for you? A worm farm is a great, small scale set up appropriate for apartment living (on a balcony) or a larger scale set up with some yard space. The great thing about worms is, if set up correctly and given the right food scraps (they can be picky with certain things), they require little maintenance to manage.

To sum it up quite simply, the worms eat bacteria and fungi that grow on your food scraps (decomposing the food), and therefore, the worms end up processing the food as well. The worm castings which result (worm poop and wee) from them processing vegetable and fruit scraps are a garden gold fertiliser, with beneficial microbes and few to no pathogens.

For the action steps, think of your compost bin in layers:

  • Vessel/container your worms will live in
  • The bedding or foundations which they start on
  • Their conditions, such as temperature, location and moisture
  • Food scraps you feed them

Action Steps (bear with us as there are lots!)

Equipment list
  • Kitchen caddy compost bin to collect food scraps
  • Worm farm home/container (eg. something like this) or a worm bag (eg. like this one)
  • Worms from friend’s existing worm farms or from a gardening store (eg. here)
  • Cardboard, newspaper, recycled paper (for bedding)
  • Compost (for bedding)
  • Hessian (coffee) sack
  • Chopping board and cleaver or tube and spade to chop up waste
  • Digital kitchen Thermometer to check temp
  • Bucket to collect scraps and worm liquid from under the worm farms themselves
  • Old milk bottle to freeze in days over 30°C
  • Shade cloth to protect from heat
  • Plastic or tarp for heavy rain
Storing your worm’s food
  • Set up a compost food caddy in your kitchen to ensure you collect all of your food scraps.
  • If storing worm food before you feed them, place 4-6 litres of carbon bedding (such as cardboard, newspaper, soil, compost) in the base of a bucket to soak up liquid and stop unwanted odours. Bedding can be used later to cover the chopped food when you place it in the worm bins.
  • Find the right home for your worms from the start. Worms are living creatures – treat them like your pets! The right place will be somewhere with a stable temperature and moisture, with the ideal temperature for worm production is 18-23°C.
  • Worm activity slows down as it gets colder. Under 12°C they slow down a lot, but this can be avoided by placing them in the sun briefly once the temperatures start to drop. We recommend a digital kitchen thermometer for checking your worm farm temperature.
  • As temperatures increase above 30°C, worms often get too hot and slow down again, and will start to die over 40°C. If you know it will be a sunny and warm day, place them under the shade of a tree, awning or shade cloth.
  • On hot days in summer over 30°C, soak hesson coffee sack in water and place it on top of the worm farm to assist in evaporative cooling.
  • To keep your worms cool, put old milk or drink containers filled with water in the freezer overnight and then add them to the farm in the morning.
    Worms leave eggs behind if things happen to go badly in harsh conditions. Thankfully the populations will recover, but you would need to reduce the food being fed while in recovery.
  • Worms like an environment with around 70% moisture. This will need monitoring in the initial set up phase.
  • It is recommended to leave the bottom tab open of your worm container set up and place a container underneath to collect any liquid. A good worm farm will not produce any liquid as this indicates that the system is too wet and over 70% moisture. This would promote undesirable anaerobic microbes which are not great for your worms.
  • Ensure your worm farm is under cover when raining. This could be under an awning or a tarpaulin, to avoid saturation in heavy rain.
  • Mix a base for the bottom of the bin of cardboard/shredded paper and good compost. A good mix of carbon material is beneficial; this could also include shredded leaves, paper straw, peat moss, soaked coir, spent mushroom substrate and aged horse manure. Chemical free wood shaving is also excellent but avoid sawdust as this will compact and cause an anaerobic environment (again not ideal for the worms).
  • Wet the materials to 60% moisture, squeezing a handful of the mixture and checking for several drops of water to be expressed in between your fingers. If it flows out between fingers it’s too wet and if there are no drops at all, you will need to add more water.
Adding Worms
  • Buying or obtaining some worms from a friend is a great way to get started. Worms can be taken from a productive system every couple of months without slowing their production too much. With the right conditions, worms will reproduce and within a few weeks should double in number or more.
  • Getting a mix of worms is good as they will find their natural level in a system. However the red wiggler, Eisenia Foetida, is said to be a flexible worm that will flourish in the right conditions.
  • Add worms by mixing the bedding material the worms came in with the base materials.
  • Sprinkly some water to bring moisture to about 60%.
  • Disperse a litre of food scraps and then cover with 1 litre of bedding mix.
Feeding your worms
  • Add chopped food 0.5cm high on top of the mixed bedding material.
  • A good amount in a black worm bin would be 2-3 litres and the same amount of bedding mixture (the compost/cardboard/soil combo) to be placed on top.
  • Observe when the food is gone, and add more.
    Ideally feeding would happen every three days but once a week will also be enough for them.
  • Placing the bedding mixture on top of the food scraps helps keep new food waste covered and prevents unwanted pests. It also absorbs moisture and promotes beneficial fungal colonisation.
  • Cover with hessian sack (you can grab one of these from a local coffee shop or local roaster).
  • As you begin to layer your new worm farm, occasionally loosen the layers of food and bedding material before feeding by placing glove fingers or a trowel into lower layers, to allow air in to prevent anaerobic conditions. Try not to mix layers while aerating.
Harvesting worms castings
  • Take the bottom tray off your worm farm and place castings into sunlight (the processed food and soil looking material, where there she should be little to no unprocessed food remaining).
  • Worms will make their way away from the light. You can then gently scrape the top of the casting away and place in a seperate container, trying not to remove worms.
  • Doing this in stages allows a few minutes for the worms to make their way down away from the light.
  • Add any worms in the bottom of the tray back into the active worm bin above.
  • If possible, leave the casting in a warm dark space before use to allow reduction in moisture.

Key points to remember:

  • 10-25°C optimal temperature for worms
  • Darkness and not in direct sunlight
  • Ensure moisture if materials are dry
  • Chopped up food scraps as their food*

*Chopping the food up in small pieces creates more surface area for the bacteria and fungi to decompose the food

Extra resources and tutorials:




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