Irish moss, also known as Scotch moss or Sabina subulata, is a flowering perennial commonly grown as a ground cover because of its short, dense growth habit. The plant naturally self-seeds and can rapidly spread to cover an entire lawn in only a few years. Irish moss blooms during spring and summer, producing small, white flowers. Native to Europe, Irish moss is hardy in planting zones 4 through 10 and thrives in most regions of the U.S. with minimal care.
Plant Irish moss in a location that receives light to moderate shade throughout the day. Choose a site that consists of moist, well-drained, fertile soil for optimal growth. Space Irish moss plants 6 to 10 inches apart.
Water once every five days during the first two months of growth to help establish the plant. Reduce watering frequency thereafter to once every week to prevent the soil from drying out completely. Do not water during winter, when the plant is not actively growing.
Fertilize Irish moss once every other month using a complete 10-10-10 NPK fertilizer. Water both before and after applying to prevent root burn and release the nutrients into the soil. Apply according to the manufacturer's directions for the best results.
Prolong the blooming season by removing faded and dead Irish moss flowers as soon as possible. Pinch off the flowers near their point of origin and a new blossom will form within a few days to replace it.