Worm Farms and Liquid Gold: The Gardener's Secret Weapon

If someone told you that you could turn your kitchen scraps into the best fertiliser your garden has ever seen, using nothing more than a box of worms, you would probably be a bit sceptical. But worm farming is the real deal. It is simple, it works in tiny spaces, and the stuff your worms produce is genuinely some of the best plant food on the planet.

Why Worm Farms?

Worm farms turn food scraps into two incredibly valuable products: worm castings (basically worm poo) and worm juice, often called “liquid gold.” Both are packed with beneficial microbes, plant-available nutrients, and humic acids that improve soil structure.

A worm farm also keeps food waste out of landfill, where it would produce methane. So you are feeding your plants and helping the environment at the same time. Not bad for a box of wriggly little creatures.

Choosing Your Worm Farm Type

There are several styles of worm farm, and each has its pros and cons.

Stackable tray systems (like the Can-O-Worms or Tumbleweed) are the most popular in Australia. They have multiple trays that stack on top of each other, with a collection tray at the bottom for the liquid. As the worms work through the food in one tray, they migrate upward to the next tray. This makes harvesting castings easy: just remove the bottom tray.

Bathtub or continuous flow systems are great for larger households. An old bathtub on legs, with a drain fitted at the bottom, works surprisingly well. Feed from one end and harvest castings from the other.

Worm bags (like the Urban Worm Bag) are a newer option that hangs from a frame. You feed from the top and harvest from the bottom. They are lightweight and work well on balconies.

The Right Worms

Not just any earthworm will do. The worms you find in your garden are burrowing worms that like to dig deep. Composting worms are surface feeders that thrive in organic matter.

The two best species for worm farming in Australia are:

Red wrigglers (Eisenia fetida) are the most common composting worm. They are voracious eaters, reproduce quickly, and handle temperature fluctuations reasonably well.

Tiger worms (Eisenia andrei) are closely related to red wrigglers and are often sold interchangeably. They have distinctive striped markings and are equally excellent composters.

You can buy starter packs of composting worms from garden centres, hardware stores, or online suppliers like Kookaburra Worm Farms, Bunnings, or local worm farming enthusiasts.

Start with about 1,000 worms (roughly 250 grams). They will multiply quickly once they are settled in.

Setting Up Your Worm Farm

1. Prepare the bedding. Fill the first tray with damp shredded newspaper, cardboard, and a handful of aged compost. This is your worms’ home. It should feel like a wrung-out sponge, moist but not dripping.

2. Add the worms. Tip them gently onto the bedding and let them burrow down in their own time. Leave the lid off for a few minutes under a light, as worms dislike light and will head downward.

3. Start feeding slowly. For the first week, add only a small amount of food. The worms need time to settle in. Gradually increase the amount as they start eating more.

4. Cover the food. Place a damp sheet of newspaper or a worm blanket over the food to keep conditions moist and dark.

What to Feed Your Worms

Worms will eat most fruit and vegetable scraps, but some foods are much better than others.

Great foods: Fruit peels, vegetable scraps, tea bags (remove the staple), coffee grounds, crushed eggshells, soaked cardboard, shredded newspaper, avocado skins (cut up small).

Feed sparingly: Bread, pasta, rice (cooked, in small amounts), leafy greens (can heat up if added in bulk).

Do NOT feed: Citrus fruit (too acidic), onions and garlic (worms hate them), meat and dairy (attracts pests and smells terrible), oily or salty foods, pet droppings, glossy or coloured paper.

Harvesting Worm Castings

Worm castings are dark, crumbly, and smell like fresh earth. They are packed with nutrients and beneficial microorganisms that improve soil health and plant growth.

In a stackable system, harvest is simple. Once the bottom tray is full of dark castings and the worms have migrated upward, remove the tray and use the castings in your garden. Replace it on top as your new feeding tray.

You can use castings as a top dressing around plants, mix them into potting soil, or brew them into a compost tea for liquid feeding.

Worm Tea: The Liquid Gold

The liquid that collects in the bottom tray of your worm farm is often called worm tea or worm juice. It is a concentrated liquid fertiliser that your plants will absolutely love.

To use it, dilute the liquid until it looks like weak tea (roughly 1 part worm juice to 10 parts water). Use it to water your plants, or apply it as a foliar spray.

Troubleshooting Common Problems

The farm is too wet. Add more shredded newspaper and cardboard to absorb excess moisture. Make sure the drainage tap is open.

The farm smells bad. You are overfeeding or adding the wrong foods. Remove any uneaten food, add dry bedding material, and cut back on feeding.

The farm is too hot. Move it to a shaded spot. In Australian summers, temperatures above 30 degrees can stress or kill worms. A cool, shaded spot (south-facing wall, under a tree, in a garage) is essential.

Worms are escaping. This usually means conditions inside the farm are wrong. Check for overfeeding, excess moisture, or extreme temperatures. Leave a light on near the farm for a night or two; this encourages them to stay inside.

Tiny vinegar flies. These annoying little flies appear when food is exposed. Cover food with a layer of damp newspaper and bury scraps under the bedding rather than leaving them on top.

Perfect for Apartments and Small Spaces

One of the best things about worm farms is that they take up barely any space. A standard stackable worm farm fits on a balcony, in a laundry, or even under a kitchen bench. They produce no odour when managed correctly (really, none at all), and the worms are silent housemates.

If you live in an apartment and thought composting was not an option for you, think again. A worm farm is the most efficient way to turn food scraps into plant food in the smallest possible space.

Where to Buy in Australia

Most Bunnings stores carry worm farms and starter worm packs. You can also find excellent worm farms from Australian suppliers like:

• Tumbleweed (available at most garden centres)
• Maze Products
• Kookaburra Worm Farms
• Urban Composter
• Local community gardens (often sell worms at great prices)

The Bottom Line

A worm farm is one of the best investments you can make for your garden. For a small upfront cost and just a few minutes of attention each week, you get a steady supply of incredible, free fertiliser. Your plants will be healthier, your food waste will drop dramatically, and you will have the quiet satisfaction of knowing that your little worm army is doing great work behind the scenes.