A worm farm is one of the easiest ways to turn everyday kitchen scraps into nutrient-rich fertiliser and help your garden to thrive.
You don’t need much space to use an off-the-shelf worm farm and can get up and running quickly.
Almost half of household waste is organic, and when sent to landfill it releases greenhouse gas methane. A worm farm helps recycle organic waste into something very useful for your garden.
Setting up your worm farm
Worm farms are designed to create the ideal environment for composting worms, with stacked trays that allow for good airflow, drainage, and easy harvesting. As food is added to the upper tray, worms naturally move upward, leaving behind nutrient-rich castings in the lower tray ready for harvesting.
Start by positioning your worm farm in a shaded, well-ventilated spot, away from direct sun and extreme temperatures. This helps keep conditions stable so worms remain active and productive year-round.
Once in place, add bedding material such as bedding blocks, damp cardboard or newspaper, along with a starter population of worms. If using a bedding block, soak it in water first, then crumble it before spreading it across the base.
Placing a worm blanket over the bedding also helps create a dark, moist and aerated environment, encouraging the worms to settle in and begin processing organic material.
Keeping your worm farm healthy
Maintaining a worm farm is simple and only requires occasional checks.
Worms thrive in a moist environment that feels like a wrung-out sponge, so monitor the bedding to ensure it is not too dry or too wet. Add water if it’s dry or mix in dry paper if it’s too wet.
It’s best to feed your worms small amounts regularly, only adding more food once most of the previous scraps have broken down. As long as conditionals remain balanced, a typical household worm farm can process several kilograms of food scraps each week.
Worms will happily eat fruit and vegetable scraps, coffee grounds and crushed eggshells, along with materials like shredded paper or newspaper. Avoid adding meat, dairy or oily foods.
Try burying food beneath the surface, which helps prevent unwanted pests and odours.
Harvesting worm farm by-products
Your worm farm will produce two valuable by-products.
The first is worm castings, a dark, crumbly material that can be mixed into garden beds or potting mix to improve soil structure and boost plant growth.
The second is liquid fertiliser, often called worm tea, which can be diluted with water and used to feed plants directly. Drain the liquid regularly from the worm farm’s tap to prevent excess moisture building up in the system.
Using these outputs regularly helps create a healthier garden. Plants benefit from improved nutrient availability and stronger root development, while soil becomes more resilient and easier to work with.
If you are also composting at home, worm farming works hand-in-hand, helping break down finer materials and speeding up the overall process. Use your compost bin for larger garden waste like leaves and prunings, and add smaller kitchen scraps to your worm farm, where worms can break them down more quickly. You can also move partially composted material from your compost bin into the worm farm to speed up the final stage of decomposition.
Get more tips on building your composting system in this helpful article on How to make compost for your garden.
A simple, sustainable system
A worm farm does not require constant attention, but a little care goes a long way. By keeping conditions stable, feeding appropriately, and harvesting regularly, you will have a reliable system that turns waste into something genuinely valuable.
It is a simple, sustainable addition to any garden and an easy way to support healthier plants all year-round.
As an alternative to buying an above-ground worm farm, check out How to create an in-ground worm farm by experienced community member @Nham.
