Irish moss (Sagina Subulata) is really not a moss at all, but a perennial flowering plant. Commonly used as a groundcover or as filler between stepping stones, Irish moss grows in sunny to partly shady locations with cool temperatures. Although Irish moss requires consistently moist soil, it repays the gardener with a groundcover that remains green all winter and will stand up to kids and pets. Start your Irish moss seeds when temperatures are over 65 degrees F.
Remove all weeds from the planting area. In small areas, pull weeds by hand. In larger areas, consider using an herbicide containing glyphosate, according to package directions.
Till the planting area to a depth of 10 inches. Add a 2-inch layer of compost and a 3-inch layer of sand to the soil and till it to a depth of 8 inches. Level the area with a rake.
Water the planting area and allow the soil to drain.
Scatter the Irish moss seeds, either by hand or with a broadcast spreader, thickly over the planting bed.
Lightly blend the Irish moss seed into the top layer of the soil with a rake. Don't cover them too deeply as they require light to germinate.
Water the planting area to keep it moist while the Irish moss seeds germinate, which should occur within two weeks.