White marble rocks in a landscape can offer a visually pleasing way to prevent soil erosion and maintain soil moisture retention. Adding white marble rocks to a flower bed can help reflect much-needed light on sun-loving plants. Applied in a 2-inch layer, the white marble rocks form a mulch that can help keep weeds at bay. Some homeowners also lay down the marble rocks to make pathways through the landscape. Despite their many uses, white marble rocks often become discoloured from decomposing leaves or plant life and require regular cleaning to restore their sparkling white colouration.
Pressure-wash the marble rocks monthly to help maintain the rocks' overall white appearance. Washing the rocks with a high-powered stream of water will help prevent the rocks from becoming discoloured from leaves and dirt.
Rake away leaves or plant debris from the surface of the rocks. Dig the rake deeper into the rocks to gently turn them as you pull the rake through their surface to remove all debris that may discolour the rocks further. Pick up the debris with your hands and dispose of it.
Add two squirts of mild dish soap to a garden sprayer to remove stains. Fill the garden sprayer with warm water. Saturate the stained areas, using the garden sprayer. Pressure-wash the soap and water mixture from the white marble rocks to remove the stains. Thoroughly saturate the area so all soap is removed and existing plant life does not suffer.
Never use bleach or abrasive cleaners on marble rocks. Marble is porous and will be damaged by harsh cleaners. It also may suffer further staining from acid-based cleaners.