A green plant that grows low on surfaces, moss is small and spreads rapidly on top of other plants, grass, concrete and even wood benches. The plant grows in clumps and is found in areas that are damp with low light. Once removed, moss returns unless you use an agent that destroys the plant's small roots. When removing moss from a wood bench, you must destroy all of the plant's spores, roots and fragments.
Mix 1/2 gallon of warm water from a sink, 1 cup of chlorine bleach and 1 cup of washing powder in a bucket. Wear protective gloves. Stir the mixture with a scrub brush.
Move the wood bench to a surface away from plants and other foliage. If the bench cannot be moved, place a dust sheet or plastic sheeting under the bench to cover the surface below.
Pour the soap mixture slowly and evenly over the moss. Let the mixture sit for five minutes. If the mixture begins to dry, spray the bench with water from a hose or if you have any remaining mixture in the bucket, pour it over the bench.
Spray the bench thoroughly with water from a hose including the underside of the bench and any crevices.
Inspect the bench for any moss the mixture missed. If any moss if found, repeat the process.
Dry the wood bench with a towel.
Apply a coat of wood stain or paint to the bench, if the bench's paint is fading. You can also use a commercial moss and algae remover to clean moss from your wood bench.