How to Make a Worm Farm

What can we do with all our kitchen vegie scraps? Throw them into a compost bin, of course, but even better we could feed them to a multitude of worms who will produce powerful liquid fertiliser and nutrient-rich castings to spread over the garden. Most kids will really enjoy putting together a worm farm with an adult and watching those wiggly worms settle into their new home and then help break down and recycle kitchen scraps including leftovers from their own plates. There are many styles of worm farm commercially available or you can try your hand at making your own. Photo credit: Anita Peluso – Bloomin’ Workshop on Flickr.

You will need:
3 (same sized) waterproof boxes
A lid for one box, or hessian sheet or piece of cardboard
Insect screen to fit into the bottom of the boxes
Drill and bits (1/4 inch)
Two bricks to support the worm farm

alternatively: A store bought worm farm (be sure to follow the manufacturer’s instructions).

1000 – 2000 composting worms*
Well decomposed compost
Potting mix

  • Firstly choose a place outdoors for your worm farm. Make sure it’s shady with good drainage.
  • If you are making your own farm, drill evenly spaced drainage holes in you container.
  • Line the bottom of your first container with three sheets of damp newspaper, and then half fill with compost, shredded damp newspaper and potting mix. You may also like to add grass clippings or garden soil.
  • Stand the container on the bricks so that extra water can drain out of the holes. You could put another box underneath this to catch all that good stuff and pour it (usually diluted) onto your garden.
  • Add your feisty, raring to go worms
  • Water until moist and then add your lid or hessian sheet
  • Add food weekly – just a small amount at first and then increase the amount over time as you get a feel for how much they will break down. If there is uneaten food remaining then you know you will have overfed your worms. Wait until this is eaten before adding more. After adding the food scraps, make sure you cover it all with a layer of compost or soil to avoid attracting vinegar flies. As your worm population increases, so will the amount of food you can put in.
  • Water your worm farm every few days, or more regularly if it’s hot and dry. Don’t make the worm farm soggy – just moist, plus there is moisture in food scraps.
  • After 6 months your worms may have out-grown their first container. Now it’s time to place the second container (with holes drilled in the bottom) over the top. Put the food scraps in the top box and they will move up through the holes to eat them!
  •  After a few months the worms should have moved up into the second box and you can use the castings in the first box on the garden as compost. Just place the castings around your plants and water in. Don’t pot anything in the castings alone.
  • Add a new box as they outgrow each level.

And what will they eat?
Left over cooked vegetables
Left over cooked fruit
Fruit peelings
Vegetable and fruit scraps and peelings
Coffee grounds and tea bags (though not every day)
Crushed egg shells
Saw dust
Soaked cardboard
Hair clippings and vacuum cleaner dust
Stale biscuits and cakes

Avoid onions and garlic and a lot of citrus peel. They may not like tofu, beans or banana peels. Steer clear of feeding them meat and poultry or dairy products as these will smell and attract insects and vermin.

Food scraps should be small and partially decomposed before adding them to the worm farm. Keep them in a sealed plastic container for a couple of days.

For further information please do a search on the web for “make your own worm farm” but you can also check out:

Vermicomposting on You Grow Girl

* Composting worms are Reds, Tigers or Blues in Australia and Red Wrigglers in the US.