A worm farm is an easy, cheap and efficient mechanism for converting organic waste into liquid feed (worm wee or vermileachate) and rich organic compost (vermicompost), using the natural action of earthworms.

Each worm farm houses a large number of rapidly breeding earthworms whilst they process organic waste. The products of the worm farm (vermicompost or worm castings and vermileachate or worm wee) are easily harvested and can be used in your garden or farm through direct application or irrigation. From the vermicompost can simply be produced, reputedly the finest compost tea.

Worm farms come in various designs and are made of different materials. Some contain a series of trays or compartments with holes in the bottom of each for the earthworms to migrate through. Fresh waste is placed in the top tray and processed waste is harvested from the bottom tray. The earthworms migrate upwards towards the fresh waste in the top compartment. Once the vermicompost is ready in the bottom tray, it is removed, and the tray is refilled with fresh organic waste and moved to the top of the wormery. Alternatively, as seen in "Our Green Worm Farm", the worms move laterally, enabling an easy and more proficient operation with greater exposure to oxygen and added capacity.

Worm farms require protection from the elements and are easy to manage and odourless. The size of the worm farm is determined by the volume and type of organic material to be processed, and your budget.