The ideal ground cover for a Japanese garden is moss. Growing on rocks, between paving stones, over logs and around stone wash basins, these tiny plants create the feeling of age and permanence that the Japanese admire. Their rich colors and velvety textures have made them a favorite of Japanese landscape designers, who have collected and cultivated them for centuries, drawing upon hundreds of different kinds. There is a moss for almost any moist location. As a group, they withstand heat and cold, grow slowly and live a long time; some moss gardens in Japan are hundreds of years old.
True mosses grow 1/16 to 24 inches tall. They have many tiny flat leaves and stems that are often too closely packed to distinguish. The leaves expand when wet and close up when dry. Thousands of plants bunch together to make a patch of moss. Like ferns, mosses grow from spores. The spores develop green threadlike branches called protonema, which push into the ground and eventually develop leaves. The plants do not have true roots but attach themselves by tiny rootlets to the material on which they grow. By absorbing water, mosses allow moisture to soak into the ground gradually and help enrich the soil when they decay.
HOW TO GROW. Mosses grow throughout the United States. Most do best in open shade, where there is some sun in the morning and late afternoon, but a few kinds tolerate deep shade. All thrive in very moist, fertile soil. The easiest way to acquire moss for the garden is to transplant a strip from your own or a neighbor's woods; few nurseries carry mosses. If possible, lift the moss attached to part of the material on which it is already growing; otherwise gently remove moss with a wide knife, tearing as few of the threadlike protonema as possible. Press the strip into muddy soil on rocks or at the base of trees. Keep moist but not soggy; too much moisture without sun will cause the plants to develop mold. If the leaves dry out, plants are revived by soaking with water.
STARTING MOSS WITH A MILKSHAKE
Moss gives a garden that prized feel of autiquity. Even bright new brick patios and walkways acquire a patina of age when moss sprouts betweem the cracks. Unfortunately, if you wait for moss to show up on its own, you may be waiting a long time. Hasten the process along by mixing up a moss milkshake. Start with a clump of moss from your own yard (check moist, shady areas to find a likely patch) Crumble the moss into a blender and add buttermilk and water in equal parts. Process on "Mix" until the concoction is well blended. If it's thick like pancake batter, add some water and thin it to cream-soup consistency. Pour your moss milkshake wherever you want moss to grow. Keep moist and soon the bits of blended moss will regenerate into whole roote plants and colonize the area.
This was taken from Rebecca's Garden - Garden Tips
USEING THE MOSS MILKSHAKE FOR POTS AND STATUARY'S
For those of you that want to grow the moss on clay, or cement pots, or on statuary items to give them that aged look, use the above receipe, but instead of pouring it on you would paint it on with a paint brush, with the same after care as above.