Some effective products for cleaning gravestones include D/2 Biological Solution, ammonia and clean water. The first step is to identify the material of the gravestone, followed by choosing a cleaning method.
Clean water and a soft scrub brush should be used to saturate the stone and remove any plant or debris on the surface. D/2 Biological Solution may be used to clean heavy growth using a brush or pump sprayer. Finally, one part ammonium hydroxide diluted with four parts water may be used to clear plant life. Detergents, chlorine bleach and household cleaners should not be used to clean gravestones.