Stone walls and walkways have made a comeback recently in new home building. These stones generally require next to no maintenance because, well, they are made of stone. However, mold, lichens, and other plants and fungi often grow on them. Especially in damp and shady areas. To clean the stones, brush with a solution of 1 cup of bleach in 4 cups of water. This will kill the spores, keeping the stones clean longer.
