How to Remove Moss from Keystone Retaining Wall Blocks

Retaining walls are used to stabilize a hill to prevent it from eroding, or to create a flat surface on a hillside on which you can plant a garden or flowerbed. The walls can be built out of many different materials, one of which is keystone retaining wall blocks. These are blocks that contain fiberglass pins which allow you to stack the blocks without using mortar. The blocks are fairly low-maintenance, but you may find that moss grows on them.

Things You'll Need

• Power washer or garden hose
• Bleach
• Stiff brush

Show More

Instructions

1. • 1

     Spray the blocks down with a power washer or hose at full power to remove any loose moss from the surface of the blocks.

   • 2

     Mix a solution of one part bleach to 10 parts water.

   • 3

     Scrub the remaining moss off the walls, using a stiff brush and the bleach and water solution. If you get any of the bleach solution on any plants, rinse them off with clean water immediately.

   • 4

     Spray the blocks down with the power washer or hose again to remove the bleach solution.