God knows how many species of Mosses exist. They differ from other plants in many ways: They do not have “veins” (water-bearing vessels) and do not flower (no flowers = no seeds), are small, herbaceous and unlike other plants do not absorb water or nutrients through their roots but through the leaves.

Orchid growers use Mosses as soil conditioners to increases the soil's capacity to hold water and nutrients. Mosses are also wrapped around the roots of mounted orchids to retain moisture.  Over the years, four “types” of Mosses were chosen by orchid growers from experience. Sphagnum Moss, Peat Moss, Sheet Moss and Bog Moss..

Sphagnum moss: Sphagnum moss is a genus of many species that grows on the top of bogs. It is harvested while still growing and dried out before use. I know many web sites praise sphagnum moss, however, in time (6-9 months), Sphagnum moss becomes sour and need to be replaced. Adding charcoal helps to increase the “life” of the Moss by a year. Sphagnum moss has antiseptic capabilities and has been used to dress wounds. As a media, it can be used alone, or mixed with other media, such as perlite, charcoal or expanded clay.

Sphagnum peat or Peat moss: Peat moss is the decaying matter found underneath the Sphagnum moss, dried and pulverized. Peat Moss has excellent water retention properties, is soft, easily compressed and has a low pH that increases acidity. It helps to control and restrict the growth of fungi. However, it decays very quickly. Coir is a better substitute. Can be used in small amounts mixed with perlite.

Sheet moss: Sheet moss grows on rocks or trees. It retains water well and can keep a potting mix more open. Like Peat moss, it also restricts the growth of fungi. It is primarily when mounting orchids on slabs or tree limbs to help the plant to establish itself.

Bog moss: Bog moss is a living moss, gathered in sheets or clumps and used as a single ingredient for potting a variety of orchid species because it’s salt‑free and has a long life. Bog moss can be kept alive if it is watered with clean or rain water.

BE AWARE: Harvesting of moss peat is generally considered to cause significant environmental damage as the peat is stripped with little or no chance of recovery.