Mosses are quite different from other plants in terms of biology and care. Instead of having true root systems, mosses have small fibers called protonema that attach them to soils and other surfaces -- they obtain their nutrition from the air rather than from soil. They also require less sunlight than other plants, and many species actually thrive in dark and shaded conditions. Mosses are slow-growing but very durable -- they can be grown in nearly any garden with only minimal effort.
Select a location that is shaded from direct sunlight for most (but not all) of the day -- locations that are only exposed to sunlight from the north or east are ideal. Choose a planting site that is close to a source of water if possible.
Test the pH of the soil with a soil testing kit -- the ideal pH for growing moss is between 5.0 and 6.0, with 5.5 allowing some wiggle room. Reduce the soil pH, if necessary, with aluminum sulfate -- the exact amount required depends on the soil's current pH. Test the soil 24 hours after applying the aluminum nitrate and make additional adjustments if necessary.
Remove any leaves or debris from the soil, then tamp it down to compact it. Place the moss on the soil if it comes in sheets or layers, or dig a hole to place potted moss.
Use a misting garden hose attachment to keep the moss damp for the first three weeks after planting it. Mist the moss at least once a day during dry weather conditions -- mosses can survive dry conditions but they require dampness in order to thrive.