Anyone who has happened upon a velveteened log in the woods or glimpsed emerald-draped statuary is likely to be seduced by moss’ color-saturated sumptuousness. But it is essential for those hoping to lay a carpet in their own backyards or coax the spread of an existing patch to understand the quirks of this ancient plant.
Like many 400-million-year-olds, moss is particular about its environment. Shade or semi-shade is usually a necessity. So are a consistent source of ambient moisture and vigilant maintenance to keep it free of weeds and debris (because mosses are nonvascular—no roots—they rely on their leaves for transportation of nutrients and moisture). Experts suggest setting down netting on top of moss in the fall and regularly emptying it of fallen leaves
Rock cap moss, Dicranum, will prosper in deep shade. Transplant it when leaves are already on the trees, as sun can quickly inflict harm. This plant will grow on top of rocks and boulders. Adopt it as a ground cover instead of grass for shady areas.
Hair cap moss, Polytrichum commune, prefers medium shade to partial sun, and sandy, acidic soils. If the soil is sufficiently moist, it can tolerate almost full sun. This variety can handle light foot traffic.
Sheet moss, Hypnum, one of the most common types of moss, thrives in deep shade and has a great transplant success rate. Its dense green mats can handle light foot traffic. Use it between stepping stones or, because of its low growth habit, as a ground cover to highlight other low-ranging plants.
Taken from Grow Your Own, Garden Design April 2011 by Deb Schwartz