Worm Farming

Worm farming uses worms to turn food scraps into nutrient-rich compost for healthier soil.

Compost can also be produced using worms, a process known as worm farming or vermiculture. This method uses an enclosed system in which worms consume food scraps, digest them, and produce nutrient‑rich worm compost that improves soil health.

In New Zealand, tiger worms are most used for worm farming, although red worms are also suitable. Worm farming follows the same principles as composting, but because it does not generate heat, it is considered a form of cold composting. As the worms consume and break down organic material, they produce vermicast and worm tea that contains nutrients that support strong leaf growth, robust roots and stems, and healthy flower and fruit development.

If you have mostly kitchen waste and live in a home with little or no outdoor space, a worm farm is a good option. Casts and worm tea are excellent for plants that must be diluted to the color of weak tea—typically about a 1:10 ratio before applying to the plant.

Worm’s Feed

What you can and cannot add to your worm compost.

What worms like	What worms don’t like
Most fruit and vegetable scraps	Spicy food, chilli, onion, garlic
Coffee grounds and teabags	Meat and milk products
Aged horse manure	Flour product
Dirty paper	Large amounts of cooked food
Crushed eggshells	Garden waste
Vacuum cleaner dust	Shiny paper
Hair	Citrus / very acidic food

Common worm farm problems

Problems associated with worm farming and possible solutions for it.

Problem	Cause	Solution
Rotting food	Too much for population	Feed less
Fruit / vinegar flies around farm or small white bugs and worms	Too acidic	Add lime to increase pH
Worms climbing up sides Worms very fat and pale	Too wet	Add paper products and dry leaves, gently fork holes in the working layer.
Ants	Too dry or acidic	Add water/lime If your worm farm is on legs, place each leg in a container of water to stop such pests from getting in.
Food rotting and not eaten	Too much food / wrong food /pieces too big	Add less food, break into small pieces
No worm tea	Not enough water	Add water

How to do it

Choose a site that is sheltered from sun, wind, and rain.
For this setup, use the bin or tray method, which is ideal for homes, balconies, garages, or small outdoor spaces.
Earthworms need bedding that holds moisture and provides a suitable habitat. Add shredded paper or cardboard, straw, and partially decomposed organic matter and add a small amount of water to provide moisture.
Add 1,000-2,000 (250g -500g) worms.
Place worms on top of the bedding. They will naturally burrow away from light.
Remove the top layer, then lift off the bottom layer containing the cast. It’s ready once only a few worms remain.
Remove worm tea from the bottom level. When using, dilute the color of weak tea, usually about 1:10.
When one working layer is full, you can add another layer to your worm farm.
Place the new layer on top of the old one, add fresh bedding (paper, straw, or manure), and then top it off with more food scraps.
Add food only to the new layer. The worms will migrate slowly to the food layer.
If your plastic bin has deep layers and you want to harvest the cast sooner, you can add a layer of chicken wire instead of another plastic layer.

When choosing your site, make sure you select a warm sheltered spot that protects the compost from wind and access moisture. Consider neighbors by placing the bin away from their house.

Ensure, your compost heap should be at least 1m high x 1m wide x 1m deep or whatever size you want depending on the amount of waste you have.

Add shredded paper or cardboard to prevent wetness and smell from the start.

The next step is to add your first green waste- your first kitchen scraps. Follow the rule of adding a number of greens and browns at a ratio of 2 to 1.

Add water and ensure there is sufficient moisture to help with the composting; ensure its moisture and not dripping wet.

Spin the tumbler every 2-3 days after adding new scraps to prevent matting and keep the process aerobic, which prevents foul smell.

Tips

A home vermiculture bin should have adequate drainage holes for ventilation that ensure airflow and prevent anaerobic conditions. Keep the lid on to keep out pests and maintain moisture.
Your bin should be shallow in depth, as worms prefer the upper layers of organic matter.
Maintain a temperature range of 15–25°C and avoid extremes below 10°C or above 30°C, as worms slow down or may die outside these limits.
Keep moisture levels between 60–80%, ensuring the bedding feels like a wrung-out sponge—too much moisture creates anaerobic conditions, while too little dehydrates the worms.
Do not overfeed in the first 1–2 weeks—allow them to settle.
Add dry leaves or torn up paper products if it is too wet – the working area should be as damp as a wrung-out sponge.
Add food scraps regularly. Smaller pieces—no larger than 2 cm—are eaten more quickly and help prevent odors.

Learn more information on worm farming.

See video

Worm Farming

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