Peat Categories (4):

Peat's Categories	Plant Material Origin	Colour	Properties
Peat moss	decomposed remains of of sphagnum (such as S. papillosum, S. capillaceum, and S. palustre), hypnum, and other mosses	yellowish to dark-brown.	light in weight good porosity and water holding Sphagnum moss contain fungistatic substances that account for its ability to inhibit damping-off of seedlings Sphagnum moss are porduced in Germany, Canada, and Ireland Hypnaceous moss are mostly produced in the US
Humus	Decomposed debris of finely divided plant materials of unknown origin	dark brown to black	Contain large quantity of silt and clay particles Does not improve drainage when mixed with soil Because of its rapid decomposition rate and particle size, humus is not a desitable growing media