Setting Up a Worm Farm

A worm farm turns kitchen scraps into some of the richest free fertiliser you can get, in a footprint small enough for a courtyard or balcony. Setting one up well at the start saves a lot of trouble later, and most of it comes down to the right worms, the right spot and a gentle beginning.

The right worms

Composting worms are not the same as garden earthworms. You want tiger worms and red wrigglers, the surface-dwelling species sold for worm farming, which live in the top layer of rotting matter and breed fast. A starter amount of around a thousand worms will build up to fill a domestic farm within a few months. You can buy them from garden centres, worm farm suppliers and often through council waste programmes.

The bin and the bedding

A stacking tray worm farm is the easiest for beginners, but a repurposed tub or an old bath works just as well with drainage. Start the worms in damp bedding, shredded newspaper, cardboard or coir, moistened to the feel of a wrung-out sponge, and let them settle for a few days before you feed heavily.

• Tiger worms or red wrigglers, not ordinary garden worms
• A drained bin or stacking tray system, raised off the ground
• Damp bedding of shredded paper, cardboard or coir to start
• A shaded, sheltered spot out of direct sun and hard frost

Where to put it

Site the farm in shade, since worms die quickly if the bin overheats in summer sun, which is the most common New Zealand setup mistake. A spot against a south wall, under a deck or in a shed keeps it cool in summer and buffered from frost in winter. Start feeding lightly and build up as the population grows, and within a couple of months the farm will be producing castings and worm tea for the garden.