The most effective of all fertilizers, it is made from organic matter such as leaves, grass clippings and manure which has been allowed to rot for a few weeks or months until it has turned black and crumbly; in orchid growing, the soil-free medium, which may or may not contain compost from the compost heap, in which the plants are grown.
Material resulting from the breakdown by fungi and bacteria of waste organic matter such as leaves, grass clippings, vegetable peelings, animal manure and many other items—used in gardens as fertilizer and for improvement of soil texture. The term is also used for soilless growing mixes used for potting of orchids and other indoor plants.