Worm Farming for Beginners

A worm farm is the easiest way to turn kitchen scraps into garden gold, even if you have no garden at all. It fits on a balcony, under the deck or in the shade beside the back door, and it works year round.

The worms do the eating, you do the feeding, and in return you get rich castings and a liquid feed called worm tea. Both are excellent for the garden and far gentler than any bagged fertiliser.

Choosing and setting up your farm

A stacked tray-style worm farm is the standard choice and you will find them in most garden centres. The worms work their way up through the trays as they finish each layer, which makes harvesting the castings simple.

Use tiger worms or red worms, sold by the thousand specifically for worm farming. Garden earthworms will not do the job. Start them on damp shredded paper or coconut fibre as bedding, then begin feeding lightly once they have settled.

What to feed your worms

Worms eat most of the same scraps you would compost, but they prefer it soft and chopped small. Feed little and often, and wait until they have worked through one feed before adding the next. Overfeeding is the most common beginner mistake.

Bury each feed under the bedding to keep flies and smells down, and tuck a sheet of damp newspaper or hessian over the top to keep things dark and moist.

• Feed: vegetable and fruit scraps, coffee grounds, tea leaves, crushed eggshells, soft garden waste
• Feed: shredded paper and cardboard in small amounts
• Avoid: meat, dairy, oily food, citrus, onion and garlic in any quantity, and bread

Keeping the farm healthy

Worms are happiest in the shade and out of temperature extremes. Keep the farm out of direct summer sun, which can cook them, and tuck it somewhere sheltered over a cold snap. Coastal wind also dries a farm out, so a sheltered corner helps.

If the farm turns smelly or acidic, ease off the feeding and add a sprinkle of garden lime or crushed eggshell to sweeten it. A handful of dry shredded paper helps soak up excess moisture.

Harvesting castings and worm tea

Worm tea drains from the bottom tap. Dilute it until it looks like weak tea, then water it onto your plants and soil. It is mild enough to use often through the growing season.

The dark crumbly castings are pure plant food. Scoop them from the lowest finished tray and dig a handful through the soil around hungry plants, or mix them into seed-raising and potting mixes for a gentle boost.