Peat is a common and desirable component of many media. It is the decomposed remains of marshes and bogs. Peat varies depending on the original vegetation and its degree of decomposition. There are three types of peat - peat moss, reed sedge, and peat humus. Peat moss is the peat most often used in horticultural media.
Coarse grades of peat moss are commonly mixed with other media components for propagation and pot plant production because of their water holding capacity.