5. Irish or Scotch Moss (Sagina subulata), USDA zones 4-8. Irish (also called Scotch) moss isn't really a moss, though it looks like one. It presents a very tight, dense group of small, soft leaves with a sponge-like look. Irish moss grows extremely quickly and isn't very particular about soil, but it does do better in slightly shady areas. Usually this is sold in flats, like sod. Just cut it into small strips and place it around your pavers.