A worm bin is an effective way of processing compostable material from your kitchen and garden. It produces money saving, nutrient rich worm juice and a fertile compost that actively stimulates plant growth. A worm bin takes up comparatively little space – about the same area as a small dustbin – and the worms themselves carry out a speedy composting process. Wormeries are generally low maintenance and low-odour.
Most worm bins consist of a container – or bin – with several internal layers. These layers house worms, scraps they are currently eating and compost they have produced as well as worm juice. At the start, a colony of tiger worms is introduced to a layer of fresh vegetable and fruit trimmings, within the wormery, and quickly goes to work. The worms produce nutrient rich casts ‘vermicompost’ as they consume and digest the fresh material, they also produce ‘vermijuice’ which is a potent liquid feed for produce plants. Because they are enclosed and they take up little space they are often sited close by the house for easy access from the kitchen. The worm juice is periodically taken off through a tap at the bottom of the ‘bin’ and bottled up. Compost is removed when the bin becomes full and then the worms are set to work at the bottom of the bin to start afresh.
Wormeries can be bought to suit different sizes of garden and household. They are generally fairly compact because the worms make for a speedy composting process and so fresh material can be added every few days depending on the quantity available. A wormery is great for a small vegetable garden where a compost bin is not desired. In larger gardens wormeries are often used in conjunction with a series of compost bins. In some cases, gardeners will have several wormeries to process larger quantities of compostable material.
Position your wormery in a cool, shady spot. If you have a large wormery then make sure that access is sufficient to bring a wheelbarrow alongside it once it is full for removal of all that rich, dark worm compost.
Anything can be added as long as it is plant based – best to avoid fatty foods, cheese and meat. Pasta and rice, which often don't go so well in composts are fine in a wormery. Every few weeks you can add a sprinkling of garden lime to keep down the acidity of your composting material.
You can make your own wormery from recycled materials. A couple of polystyrene fish bins or a plastic storage box – even an old bath will work well if you have the space. The basic principle is to have a container that allows you to keep your worms in a layer of compost. Beneath the compost you need a barrier with holes (mesh works well) that allows juice to filter through but stops worms from following it. At the bottom of the wormery is a means of collecting the juice – this might be a sump with a tap in it, drainage holes that allow juice to drain into a collecting vessel beneath the wormery or a pipe that runs the juice into a separate container. The ‘bin’ should have a lid to keep out rain and hungry birds and should have ventilation holes around the top. All you need to buy are the worms themselves, these are often sold in boxes at garden centres or they can be ordered on line. If you are making your own wormery then you can tailor the shape and size to suit your garden’s needs.