All methods of composting use similar kinds of organic materials to produce compost. Ingredients include organic wastes such as leaves, twigs, dead plants and food scraps such as fruits, vegetables, coffee grounds, eggshells and nutshells. Manure often is added to outdoor compost piles, but it may not be part of worm composting, also known as vermicomposting, particularly if the worm compost bin is indoors. Worm-barrel composting and traditional composting methods also require water to moisten components, which helps to begin the decomposition process. Avoid using meats, oils and dairy products in compost.
Turned windrows and open-air composting are two common traditional methods used to make compost outdoors. The turned windrows method uses large, 4- to 8-foot tall rows or organic waste that must be turned periodically to aerate the material and produce compost. This method is feasible only for homeowners who have large tracts of land. In open-air composting, all organic matter is mixed together into one pile or in a large bin. Both methods require heat to aid the decomposition process, and often the compost is covered with dark plastic to help "cook" the waste. Gardeners need to turn the compost materials every few days to provide oxygen to the microbes that are essential for decomposition. Compost in small piles is ready for use within three to six months. Large piles of compost may take up to one year to mature.
Composting in bins or barrels that can be turned easily is similar to vermicomposting, except that no worms are used. The bin or barrel composting method also differs from worm-barrel composting because it requires temperatures ranging from 90 to 140 degrees Fahrenheit to break down organic materials. Bin or barrel composting includes using alternating layers of high-nitrogen green materials and carbon-based brown materials that must be turned every four to seven days. The method produces compost in about six weeks.
Containers used for worm composting are a matter of preference. Whether you use a barrel or a box, the method and results will be the same. Vermicomposting is a cold method of making composting; instead of heat, red worms aerate and break down the organic matter. Eisenia foetida and Lumbricus rubellus are the two most commonly used red worm species for vermicomposting. The bottom of a worm-compost barrel needs to be layered with moistened newspaper or cardboard along with carbon-based materials such as leaves. Place kitchen scraps on top along with worms. The amount of worms needed depends on the container's size. Castings, or excrement, produced by the worms results in a rich form of compost that may be harvested on an ongoing basis, unlike other forms of composting that are harvested in batches.