Encourage Development of Moss: To encourage moss on rocks, terracotta pots, or other objects in a shady garden, mix buttermilk and a clump or two of existing moss in a blender to make a slurry that can be painted on your moss-worthy items. Then, keep the environment moist until a green cover begins to form.
Ingredients: 1 Part Moss 1 Part Sugar 2 Parts Beer (or yogurt or buttermilk) Mix them in blender until it gets a creamy consistency. Coat the stones and pot surfaces with the mixture. Mist the surfaces every now and again to insure that they are moist. Moss grows best in the shade so try and move any treated objects as required until moss begins to grow.