Why Wooden Fences Turn Green and What to Do About it

Have you ever been relaxing in your backyard after a long day and suddenly noticed your beautiful wood fence is turning green? A green fence can be a shocking sight, but there are many things you can do to fix your fence and restore it to its former glory.

Wood fences turn green because of green algae (most often), mold, or mildew. Fortunately, green algae isn’t hard to remove from a fence. If your wood fence is turning green, you can power wash the fence, use a scrub brush to wash the fence by hand, or you can replace it. If you choose to wash your fence, you’ll need to use a warm water bleach solution.

As a preventative practice, after washing your fence and ensuring it’s clear from green algae, mold, and mildew, staining or painting your fence to create a protective layer over the freshly cleaned wood is something you can do. We will talk about this later. Let’s start by digging into why wood fences turn green and how to fix this problem.

Why Do Wood Fences Turn Green?

why do wooden fences turn green

So, your fence is turning green. Why? The first thing to explore is the location of your fence. If your fence is in a shaded and moist location, it’s susceptible to mildew and green algae growth. Additionally, if your fence is surrounded by plants, trees, shrubs, and rocks, this makes your fence more susceptible to the growing and spreading of green algae.

Green algae is slippery, slimy, and can be hazardous if it’s growing on a fence near or on a walkway. If green algae isn’t taken care of, it can spread fast and cover an entire area rapidly. It’s important to act as soon as you notice your fence overtaken by green algae, or even if you’re just starting to see it grow. 

Even if it’s confined only to your fence now, it can spread to the following surfaces quickly:

  • Decks
  • Porches
  • Awnings
  • Vinyl siding
  • Driveways
  • Outdoor furniture
  • Brick walls
  • Sheds

How to Restore a Wood Fence if it’s Turning Green 

At this point, are you confident your fence is being overrun with green algae? If so, let’s look at what you can do to fix the problem and restore your wood fence.

Power Washing

If you don’t own a power washer, you can take a trip to your local home improvement store to rent one. They’re usually offered at affordable rates. You can also ask your neighbors if they have one. You would be surprised how many people own power washers and other useful home improvement tools. Plus, it’s an opportunity to connect with your neighbors!

Once you have the power washer, follow the below steps to power wash your fence and remove the green algae:

  1. Remove plants, trees, shrubs, and other obstacles. You may not be able to move everything obstructing the fence completely. If this is the case, do the best you can and tie the branches together or cover them using durable material.
  2. Test an area of the fence with the power washer to see how your wood holds up.
  3. If the test went well, continue with the job. Set the power washer to 1,500 PSI, hold it two feet away from the fence, and wash the fence using a sweeping motion. Note: you can set the power washer to 2,000 PSI for areas of the fence where there are denser pockets of algae that aren’t coming off easily.
  4. Once you are finished with the power washing, create a solution that is one-part bleach and two-parts water.
  5. Use the bleach solution to hand-scrub any green algae that remained post-power washing.
  6. If you’re planning on staining or painting your fence post-wash, make sure it’s fully dried and prepped before you begin.

Using a Scrub Brush

If you do not want to rent or borrow a power washer, you can wash your fence by hand with a scrub brush. This is the cheaper option, but will also require more labor, time, and energy. If you’re looking for a hands-on project and some time outdoors, this could be a good option for you.

  1. Prepare a solution that is one-part bleach and two-parts water.
  2. Add a reasonable amount of soap that’s compatible with bleach. Mix the solution.
  3. Scrub your fence with this solution.
  4. If you are planning on staining or painting your fence post-wash, make sure it’s fully dried and prepped before you begin.

When You Should Replace Your Fence

At any time during the cleaning process, if your fence starts to break down and fall apart, it’s probably time to get a new fence.

If you think it’s time for a new fence, it may be a good idea to contact a local fencing company. The fencing company will have contractors that can come out, look at your fence, and give a professional recommendation and course of action. 

They may tell you that you don’t need to remove the fence entirely, but rather replace one part of it. But, it’s possible that they may have other solutions available as well.

What You Can Do to Protect Your Fence From Future Damage

After you ensure that your fence is free of green algae, there are preventative measures you can take to shield your fence from future damage.

Staining the Fence

Staining your fence is a quick and easy project. You can purchase a wooden fence stain from your local home improvement store. The project usually takes about a day or so. You may need primer first, so make sure to ask the workers at the home improvement store what they recommend for your specific fence.

Painting the Fence

The painting process is like staining, but it requires one more step than staining. Once you have applied your stain and it has dried and set, you can apply a layer of paint. This option is great if you’re looking for a solid color for your fence or a different look other than wood grain.

Steer Clear of Plants and Trees

This prevents the growth and spread of algae spores by allowing the fence to dry quickly and not hold in the moisture. If you already have these things located near your fence, it’s a good idea to maintain them well. Make sure you’re trimming your plants, trees, and shrubs regularly. Be sure to keep an eye on rocks and potentially move them out of the way even if it’s just a few inches away from the fence.

Regular Maintenance, Cleaning, and Observation

It’s a good idea to keep an eye on your fence and always be on the lookout for damage. If you catch any signs of damage on the earlier side, it’ll be easier to treat and fix. Regular cleaning and maintenance will help keep your fence in tip top shape and free from damage and green algae.

Final Thoughts

If you see your fence turning green, there’s no need to panic. It’s probably green algae, which is an easy fix. Remember, you have a few options to get rid of the green algae. You can rent or borrow a power washer, hand scrub with a bleach-water solution, or invest in a new fence.

In any situation, it could be a good idea to consult with a professional fencing company to get a reliable opinion and course of action. It’s always a good idea to take preventative measures to preserve your fence. With regular cleaning, maintenance, and attention, your fence will maintain its original, wooden charm for years to come.

Wishing you much success in getting the green out of your fence and preserving it for years to come!

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