Irish moss can be planted a number of ways. It can soften the edges between paving stones, or it can be planted in the gaps of a rock wall. It can be used as a ground cover that will require virtually no maintenance and will never need to be mowed or weeded. Also, it can be planted in damp corners where nothing else will grow. In the summertime, it will surprise you with a dense mat of tiny, white flowers.
Locate some Irish moss. If you already have some growing in your yard, borrow from it to start new plants. If your neighbors have Irish moss they may be happy to share it with you. You also can purchase Irish moss starter plants at a greenhouse or nursery. Plant Irish moss in the spring after the last frost.
Choose a shady spot to plant the Irish moss. Remove any weeds and loosen the top of the soil with a hoe or rake. Although Irish moss will tolerate some sun, too much direct sunlight or heat will kill it.
Create a shallow hole with a trowel or with your fingers, and plant the Irish moss in the hole, with each starter about 12 inches apart. If you are planting between rocks or paving stones, just set the Irish moss starter into the spaces.
Put a large piece of cardboard over the Irish moss. Step on the cardboard firmly so the roots will make good contact with the soil. The starters can be compressed by directly stepping on them if you wish. They are sturdy plants and won't be harmed.
Keep the Irish moss damp but not soaked, and don't allow it to dry out. The Irish moss will spread quickly and from this point will require no maintenance.