The Best Way to Remove Green Algae From a Wooden Fence

Hunker may earn compensation through affiliate links in this story. Learn more about our affiliate and product review process here.
Image Credit: Brian Hartnett Photography/iStock/GettyImages

The lifespan of a wooden fence depends on several factors including the type of wood and the maintenance work you invest in it. One issue that can deteriorate a wooden fence over time is green algae. It's not uncommon for algae to grow on wooden surfaces, especially in areas that are shaded from sunlight. Treating a wooden fence before the issue arises may prevent it.


The good news is you that don't have to replace fence boards or paint over the algae spots. You can clean green algae off a wood fence fairly easily.

Video of the Day

Video of the Day

Things You'll Need

  • Plastic sheeting
  • Rubber gloves
  • Old clothing
  • Bucket
  • Chlorine bleach
  • Scrub brush
  • Garden hose
  • Power washer


Step 1

Cover surrounding plants, grass and landscaping with plastic sheeting to protect them from the bleach solution. Wear rubber gloves and old clothing.

Step 2

Fill a bucket with a solution of one part chlorine bleach and two parts warm water.

Step 3

Dip a scrub brush into the bleach solution. Scrub the algae spots on the wood.


Step 4

Let the bleach mixture sit on the wood for 15 to 30 minutes or until you notice the spots becoming lighter. Do not allow the bleach mixture to dry on the fence.

Step 5

Rinse the bleach solution from the fence with water from the garden hose.

Step 6

Apply the bleach mixture again if the algae is still there. Let it sit for 15 to 30 minutes. Rinse it off with water from a power washer. Use a power washer with 500 to 800 psi and put the tip on the widest spray setting. Hold the power washer tip about 12 inches from the wood surface and move the wand back and forth to rinse. To give your wooden fence an even appearance, clean the entire fence rather than just the algae spots.



Use caution with a power washer. Never aim it at a person. Keep the power washer wand moving at all times; holding it in any one spot for too long can damage the wood. Avoid using hot water with the power washer.



Report an Issue

screenshot of the current page

Screenshot loading...