Vermicomposting recycles waste products using earthworms. The earthworm bin composts up to one pound of waste a day per 1000 worms. Waste fed to worms can include coffee grounds, tea bags, fruit and vegetable scraps, crushed egg shells and soft lawn and garden waste. The worms have a gizzard containing stones they ate. The food travels through the gizzard where it gets ground up by the stones. After moving through the intestines, the worms eliminate the waste, called castings. Vermicompost, made of the worm castings, contains microbes and a high amount of nutrients.
Only certain earthworms work in vermiculture. Regular garden worms prefer soil. The worms used for vermicomposting usually feed on old manure. The red wiggler, Llumbricus rubellas, are the most common, but brandling worms, Eisenia foetida, and European nightcrawlers, Eisenia hortensis, are also used. Purchase worms through mail-order companies or from a local vermicomposter. The worms reproduce quickly, often doubling their numbers within a month if given proper care.
You need one pound of earthworms, containing approximately 1000 worms, for every two household members. Provide bedding material in the earthworm bin. The bedding will hold moisture and break down slowly. Use shredded leaves, newspaper or cardboard. The worms require moist, but not soggy, conditions. The earthworm bin needs temperatures between 55 degrees and 77 degrees F. In most climates they do well placed in a basement or garage.
You can purchase bins for vermicomposting. The bins, made of black plastic, provide convenience but at a high price. For an economical choice, make your own bin. A plastic storage container, wooden box or trash bin work well but need to be about one foot deep. Drill or punch small holes in the sides and bottom to provide air and drainage. Elevate the bin in a tray to allow excess liquid to drip. The liquid, called compost tea, makes a useful fertilizer for plants. The earthworm bin also needs a lid to keep it dark and prevent insects, such as flies, from entering.
Compost time greatly increases if you chop the food waste into small pieces. Use a food processor or blender to pulverize the compost before adding it to the earthworm bin. Avoid feeding the worms anything contaminated with insecticides or chemicals. Do not put garlic, onions, poisonous plants or citrus in the bin. To prevent odors, fill the bin with only as much food as the worms will eat. Use vermicompost as a soil amendment, mulch or in potting mixes.