Urban Permaculture Design Melbourne


File:Redwiggler1.jpgThey're wild and wiggly.  They make kids giggly.  And they turn your kitchen waste into the richest most fertile compost imaginable.  Worm castings are a special treat for your plants, like feeding them chocolate (and look a bit like it too) only minus the tooth decay and regret.   So put on your rubber suit and let's dive deep into the world of worms...

Why keep worms?

  • Instead of your kitchen waste going to landfill where it stinks up your rubbish bin and produces methane gas, hire some worms
  • Worms produce a brilliant soil improver for your garden
  • Their castings and juice increase your soil's water holding capacity, so you water less
  • A little bit goes a long way .. and it never ‘burns’ your plants
  • Worms are easy to look after - they’re quiet and well behaved

Compost worms are not the same as garden earthworms - they live closer to the surface, prefer wetter conditions and eat fresher organic material like manures and mulch.

How many worms should I start with? We recommend that you start with 1,000 multiplied by the number of people in your house.  They double in number roughly every three months (faster in ideal circumstances).  A well maintained worm farm will increase its population to a comfortable amount for the space and food provided.


We supply Can-O-Worms worm farms which are our pick-of-the-bunch for a thriving worm farm, although in Summer you must keep them either in a cool garage or well watered with piece of hessian, as worms in black plastic do not survive direct sunlight.

Polystyrene box: If you’re budget conscious, you can make your own worm farm with three stackable polystyrene boxes that have holes in the bottom.  This will need to be standing on a large tray to catch the worm castings, and should be covered with a wet hessian bag or a waterproof cover if your farm is exposed to rain.

To start your worm farm, add for instance the following layers (from bottom to top):-                                                                                                
1. Thick layer of chopped up and wet cardboard
2. Thin layer of dry grass clippings or straw
3. Thick layer of partly broken down compost 
4. Your worms        
5. Worm food (see below)
6. Cover with a thick layer of damp newspaper

Where should I put my worm farm?

A well maintained worm farm will not smell or attract pests, and worms need a sheltered, shady spot that isn’t too light or hot.  It’s best to place it near your kitchen for easy access.  Eg. in the laundry, the shed, on a balcony, under a tree).

Food for Worms

Feed them chopped up kitchen scraps, chopped weeds, coffee grounds, crushed eggshells, tea leaves, animal manure (horse and cow poo is favoured).  Add wet shredded newspaper, cardboard or wet straw each time that you feed the worms to keep the worm farm smelling sweet. To increase the fertility of your worm castings, it is important to give your worms a varied diet.

Gradually increase the amount of food given to encourage poplation growth, but don’t overfeed.  Worms eat approximately the same weight of food as themselves eg. 1kg of worms (4,000 worms) eats 1 kg of food per week. A smelly worm farm or the presence of vinegar flies can also indicate over-feeding.

Don’t feed your worms citrus (lemon, orange etc), onions, meat, cheese, fatty foods (although a healthy teeming wormfarm can handle small amounts of all of these).

Water:  Keep your worm farm moist (not dripping wet). Often the moisture from vegie scraps is enough.


After about 2 months rich, dark worm castings will be building up and worm juice will start to accumulate at the bottom of the worm farm.

Worm castings and compost are the best soil conditioners.  Castings should be dug into recently watered soil, or watered in when added. If added in Spring or Summer, the area should be mulched straight after adding the castings. They can be added to any area of your garden – including vegie beds.  The worm castings fertilise the soil to encourage strong plant growth and healthier soil.  A generous handful of worm castings added to a watering can, stirred, and used straight away makes a great compost ‘tea’ to be applied to your vegies and favourite plants.

Worm juice (the liquid that drains out of the worm farm) is also worth collecting and spreading around the garden, although it's not as rich as the castings themselves.  When using worm juice, it’s best to dilute it at least ten parts water to one part worm juice so that it spreads further and has greater effect.

Problem Solving

  • Sour smell and lots of tiny vinegar flies.  Add wet shredded newspaper or straw.
  • Ants – probably because something sweet is in the compost, or the compost is too dry.  Remove sweet stuff or add water.
  • It’s normal to have slaters, springtales, mites and other organisms in the worm farm.  If it is not bugging you (ha ha), more life is a good thing!

Worm Farm for your Dog’s Waste!

Have a separate worm farm for your dog poo and don’t use castings from this farm on your vegetable area- use them in your general garden or around trees.

After worming your dog(s), collect the poo into a bucket with a little sawdust.  After a few weeks, add it to the worm farm, otherwise it will kill the worms!


Cream of Worm Soup.

(No just kidding).


So that's the low down on worms.  See also our page on compost and our courses section for upcoming Beginners Guide to Compost and Worms workshops.


Organic Growing with Worms by David Murphy