How to make a really cheap worm farm

Of the vast array of creatures that live on Planet Earth, the earthworm is probably the most important for humans. Few creatures, such as earthworms, are so essential for good plant health and growth, and therefore indirectly they are very important for human health.

Earthworms excrete a substance called humus. Humus is a dark brown/black mass of well decomposed organic matter that adds minerals and nutrients to the soil. Humus is important for plant growth, improves soil physical structure, attracts other earthworms already present in the soil and improves the biological properties.

Now is your chance to cultivate these little miracles of nature. Creating a worm farm is a great activity to do with kids who live in urban centres or in rural areas. Before you begin, it is essential that you think of a system that is ideal for your situation, whether at home or on the farm.

Choosing a system

There are quite a few worm farms on the market. A worm farm should be simple to operate; be pest, fly and rat-proof; have easy access and have a drainage point to collect excess liquids and allow ventilation.

If you are making your own worm farm use materials that will not chemically react with the contents of the worm farm. You can use plastic crates, small barrels or a concrete trough.

How to make a really cheap worm farm

This is probably the easiest and cheapest worm farm you can make. Actually a cardboard box is probably the cheapest. I made this worm farm on the run as I was building a garden and disrupted a few worms. I planned to return the worms to the area once the garden was constructed. For this worm farm I found an old crate, some twine and a piece of old hessian.

Bedding

Worm bedding is also the food source of earthworms. The bedding should have a lot of carbon. A wide variety of materials can be used for bedding in your worm farm. For this worm farm I soaked shredded cardboard (without print) in water. Then I mixed it with a handful of cow manure collected in the area and mature compost.

Other materials for worm bedding include horse manure, coco coir (fiber), straw and hay, fallen leaves and wood chips. The bedding should always be moist and loose to allow the earthworms to move and facilitate aerobic decomposition. In time the bedding will turn into humus.

What worms to use

Of the 6,000 known earthworm species, among them are the red worm (Lumbricus rebellus) and the tiger worm (Elsenia andrei). These species are especially useful for recycling organic matter back into the garden. These compost worms, as the name implies, are found exclusively in manure compost piles or in soil heavily laden with decayed animal matter.

worm farm
Worms ready to be divided into another worm farm.

Worm Food

Charles Darwin discovered that earthworms eat about half their weight per day. They eat pretty much everything that was once alive. Feed your worms all your kitchen scraps including crushed egg shells for grit and add soaked cardboard when the bedding gets a little low. I just pop the food on top of the bedding and let the worms do their job.

Can I compost meat scraps?

Worms can eat meat. Their digestive fluids are similar to those of higher animals. However adding meat to the worm farm tends to attract carnivores such as rats and cats, so it’s best to avoid this. Worms will naturally go to the food that is easier to digest leaving the meat to rot attracting flies and other greeblies.

Can I compost dog and cat feaces?

Bacteria such as E. coli and other fecal pathogens may be contained in a compost bin if contaminated fecal matter is added. Dog and cat feaces can be composted but it is not recommended to put this into your food gardens. In another article we will explain how to compost pet poo which is a similar method to composting human manure. Especially useful if you don’t have access to a local council green bin.

Positioning your worm farm

I always top the worm farm up with a little straw. This protects the worms from the harsh sun. The lid I used for this farm was a repurposed woven lid. Always make sure that your lid has holes/gaps in it to allow ventilation. Position your worm farm in the shade either under a tree or on your balcony.

Interesting facts:

  • If you cut a worm in half you don’t have 2 worms, you have a dead worm.
  • A worm is 95% water. So if you leave the worms in the sun they will dry out.
  • Worms have 5 hearts.
worm farm in shade
Worm farm in shade