Look on the sidewalk or sides of trees, and it’s clear that moss can grow naturally without any assistance from humans. But you can help it along if you have a patch in your yard—and even cultivate a new expanse. “A lot of moss gardening is good sense—but also throwing out most of what you know about gardening,” says Annie Martin, owner of Mountain Moss nursery in Brevard, NC (mountainmoss.com), and author of The Magical World of Moss Gardening (Timber Press).