If you are redesigning your backyard landscape, consider putting in granite boulders. They can add a nice touch of elegance and enable you to remove grass and other vegetation you would have to cut and take care of. However, this does not mean you are completely free from upkeep duties. If you want to keep the granite looking pristine, you need to clean it periodically.
Hose down the granite boulder as soon as you notice any stains, such as spots left over from birds or moss and grass stains. The sooner you hose down the stains, the easier it will be to remove them.
Mix a mild soap with water and soak a rag into it. Wash the granite boulder around the stained areas. If the stains are fresh they will come off fairly easily.
Spray a stone-cleaning solution onto the boulder. You can find these cleaners at most home improvement stores. Allow the stone cleaner to soak into the boulder for a few minutes.
Rub the cleaner into the stone with a rag or sponge. The cleaner is good for tough stains that may have been sitting on the granite boulder for a while.
Rinse off the soap and cleaner and dry the granite boulder with a clean rag. Leaving water on the boulder for the sun to dry can age the granite faster.