How to build your own worm farm

Put off by the thought of having your own worm farm because of the cost or the effort involved? Don't be - you can set up your own farm in less than 2 hours, for under $50 and only have to devote about 5 minutes a week to it!

close up of hands holding soil and earthworms

Fun facts about worms

  • Worms double in population every 8 weeks or so – the longer you have your worm farm the more worms you’ll have, the more they can eat and the richer the fertiliser you’ll get!
  • Compost worms are different to earthworms (i.e. the ones you find in your garden). They live closer to the surface, prefer wetter conditions and, most importantly, are hungry for your food scraps.
  • A 500g bag contains around 1,000 compost worms.

Follow these 3 easy steps and in no time you’ll be reaping the rewards of your own worm farm – and your plants will love you for it! Those little carbon crusaders and garbage gobblers will devour all of your food scraps and help you reduce your greenhouse gas emissions and carbon footprint in no time!

Step 1: Create your worm home

You don’t need to buy an expensive worm farm from the garden centre or hardware store to get started.

Here are 8 ideas for items that you could re-purpose to create your own worm castle (and save from landfill):

  1. polystyrene foam fruit boxes or crates
  2. esky
  3. old council wheelie bin
  4. fish tank
  5. bath tub
  6. dresser drawer
  7. fridge
  8. bucket (for a mini worm farm!)

Whatever vessel you choose for your worm farm, your worm home will need to have solid ventilation, drainage, insulation and protection from the elements (sun, frost) and predators. Head to YouTube to check out how to set up the container (like this one from the Garden Gurus).

You’ll need to prepare bedding for the worms. First put a couple of sheets of newspaper in the bottom of the container to stop the worms falling through the holes (they are known as great escape artists!). Next, add a bedding material like cow poo, sawdust, coconut fibre or shredded newspaper. Then, sprinkle some soil (2-4 cups) on the top, as this introduces beneficial micro-organisms.

Old tub filled with soil and food scraps

If you’ve got the space, an old bathtub can make a great home for your worm farm.

Head to your local community garden, hardware store, garden centre, local council or online and purchase a bag of worms. A thousand red wriggler, Indian blues or tiger worms should cost less than $50.

Spread the worms over the bedding and cover with a layer of damp newspaper, a hessian sack or an old piece of carpet to keep the mix cool, wet and dark. Let your new critters settle in for a week or so before you begin to feed them.

It’s important to find a good spot in the garden for your worm farm: cool, sheltered spot away from direct sunlight in summer and in a warm, sunny spot protected from frosts in the winter. Try to make it easy for yourself too – locate your farm close to the kitchen so you don’t have far to travel to feed those hungry mouths!

Step 2: Feed them

Composting worms are capable of eating up to their own weight in food scraps each day – and they’ll eat almost anything!

This includes:

  • well-chopped kitchen scraps (including leftover cooked veg), peelings, fruit offcuts, bits of veg
  • tea bags, tea leaves and coffee grounds
  • human and pet hair
  • dust from your vacuum cleaner
  • crushed eggshells
  • small amounts of bread or pasta and other processed foods
  • natural fibre (cotton, linen, wool, hessian) cloth
  • paper towels and tissues
  • garden prunings (make sure the pieces are small)
  • old mulch
  • moist cardboard
  • shredded newspaper
Old tub filled with soil and food scraps

Even a small worm farm can be a great way to reduce your waste at home.

Don’t add onion, garlic, chilli, dairy, citrus fruit (like lemons, limes or oranges), meat and bones, fish, oils or grease, or dog or cat poo, as the worms are not generally fans of these!

Step 3: Reap the rewards

Keep feeding the worms. A worm farm should be clean, so if the food is going mouldy, you’re overfeeding them. If this is the case, cut back on how many scraps you put in the worm farm for a few days to see if it improves.

Every so often add a handful of soil too, as this helps the worms grind up the food.

Worms need to breathe, so give the top 5-10cm a fluff up every now and then with a fork.  Adding paper and cardboard also keeps the feed layer open and airy.

Keep the worm farm damp and the worms well fed, and in a couple of months you’ll have a concentrated liquid fertiliser (dilute 1 part worm pee to 7 parts water) and a slow-release, biologically active solid fertiliser in the form of castings (harvest the worm poo every 4-6 months) to use on your plants and garden. Trust us, they will love you for it!

We’d love to see pictures of your new worm farms in action and use them to help inspire others. Share them on social media using #ownyourimpactwa, tag us or send us an email.

Keep reading

Up for a challenge?