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Why Does My Fence Go Green?

Wondering why your fence has turned green? In this post, you’ll read about why your fence goes green, what to do about it, and more.

Wooden fence with algae, winter trees

Having a green fence can ruin your curb appeal and eventually lead to the fence falling apart altogether. This can quickly cause other areas on your property to turn green and become damaged, such as sidewalks and even the siding on your house. But what causes a fence to turn green in the first place?

In general, fences turn green due to the presence of green algae, mold, or mildew – which form when the fence retains water. 

If you’re looking to restore your fence to its former glory days and want to learn how to get rid of green mold on the fence, keep reading. You’ll also learn ways to stop your fence from turning green again, signs of damage, and more. 

Close up of wooden fence with green mold, green trees

How To Get Rid Of Green On Fence

There are many ways to get rid of the green algae and mold on your fence, from homemade solutions and store-bought specialty products to using nothing but a scrubbing brush. Each method will work differently and the effectiveness will depend on the severity of the algae or mold on the fence.

Pressure Wash

The least labor-intensive method to removing green algae and mold on your fence is to pressure wash it off. Pressure washing can damage your fence if not done properly, so do your due diligence and research how to pressure wash your fence before diving into it. 

You’ll want to start off on the lowest setting (or between 1500 and 2000 psi) and in a somewhat hidden place to test it out first. Then you’ll stand about a foot away and spray in a quick sweeping motion. To avoid damage to your fence, be careful to not spray in one area too long.

Scrub with a Bleach Solution

Another option is to scrub the fence with a simple bleach solution containing one-part bleach and two-parts water. This will remove the green algae and mold from the fence, but is labor-intensive. 

If you plan to stain or paint the fence after removing the mildew, make sure it’s thoroughly dried beforehand. It’s also worth noting that you should never mix other cleaning products with bleach since doing so can create chemical reactions that can potentially harm your health.


Vinegar can effectively remove green algae and mold from your fence, but is another method that requires some elbow grease. You can simply spray a vinegar mixture (one cup of plain white vinegar to a gallon of water) to the fence, wait several minutes, scrub and rinse away.

This is a great option if you don’t want to use bleach or a pressure washer. You may need to adjust the vinegar to water ratio to find the best amounts for your specific fence, so keep that in mind. If the vinegar isn’t getting everything off, you can scrub with some baking soda as well.

Specialty Fence Cleaners

The easiest and fastest way to remove green algae, mildew, and mold from your fence is to use a specialty fence cleaner that’s specifically designed to remove green from fences. These are usually big bottles of fence wash that come with a sprayer and are available at your common hardware stores. To use these, you typically just spray, wait, and rinse off.

Keep in mind that many of these fence washes are made with ingredients such as bleach and should not be used around gardens, children, or pet areas. 

How To Stop Green On Fence From Coming Back

There’s no sense in learning how to get rid of green mold on your fence if you don’t also figure out how to stop it from coming back. Luckily there are a few very effective ways to prevent your fence from getting green again. 

Repair or Replace Damaged Parts

Sometimes the green algae spread too far, too fast, and causes significant decay or damage to your fence. In this case, you’ll need to repair or replace the damaged areas before continuing with the other prevention methods. 

Things such as warping, splitting, and the presence of holes are indicators that your fence needs repaired or replaced. 

Stain or Paint the Fence

Staining or painting your fence will create a protective barrier against moisture, which prevents green algae and mold. You may need to prime before staining or painting, so make sure you’re prepared before grabbing any can of paint.  The best stain or paint to use on your fence is one that’s specifically made for fences, or at least contains ingredients that protect against moisture, like acrylic latex paint. 

Before staining or painting your fence, make sure it’s completely dried and inspect between panels and posts for algae that may have been missed.

Keep Out of Shade and Keep Dry

One of the reasons fences hold on to moisture is simply that they are in a shady area, thus can’t dry out. To preserve your fence and keep algae from returning, be sure to trim trees, bushes, and plants that block the sun from reaching the fence. Likewise, you may need to move any sheds that are keeping the fence in the shade.

If moving things out of the way isn’t possible, you can use professional heat guns to dry your fence after heavy rainfalls or waves of high humidity.

Maintain and Inspect the Fence Regularly

Inspecting and maintaining your fence on a regular basis can help you see problems before they have a chance to take over. Even if the algae and mold stay away, you should inspect your fence for other damage from pests, storms, animals, and so forth. 

It’s ideal to examine and wash your fence at least twice a year, preferably once a quarter. Likewise, it’s important to check your fence for damage after storms or if you have a pest problem. If you don’t want to do the maintenance yourself, there are fencing companies that can take care of everything for you.

Can I Paint Over Green Algae On Fence?

While painting over algae or mold may temporarily hide its appearance and act as a barrier, this is not a permanent solution and doesn’t kill the source of the problem. The algae and mold will continue to spread and painting over them will cause more work for you down the road. Over time the paint will chip and fall off and will look just as bad as the algae itself. 

White picket fence with algae, dirt ground, green trees and shrubs

Remove Green Algae From Fence With Vinegar

A popular way to remove green algae from fences is to use vinegar. This is a very eco-friendly, safe, and cost-effective method but does require time and scrubbing. If you’re willing to be patient and put in some effort, you can follow the steps below to get rid of green algae and mold using vinegar.

Step 1: Remove surrounding plants and items

Start by getting everything off of the fence and out of the way, including plants and bushes. You should also trim the ones that are blocking sunlight from reaching parts of the fence, as well.  

Step 2: Spray vinegar on the fence 

Spray a vinegar solution of one cup of plain white vinegar to a gallon of water on the fence and wait 10-20 minutes before scrubbing. 

Step 3: Scrub

You can use a wide scrub brush made for fences, which will do a lot of the heavy lifting for you and reduce the scrubbing time. If you’re finding you need a little extra scrubbing power, you can use baking soda. You may find it’s better to scrub and rinse one or two fence panels at a time, as opposed to washing the entire thing first.

Step 4: Rinse 

After you’ve scrubbed away, it’s time to rinse the fence. You can do this with a garden hose or even a pressure washer set at the lowest setting. As you rinse, be sure to inspect the fence to make sure you don’t leave behind algae or miss other signs of damage.

Step 5: Dry

Once you’re happy with the results, it’s time to let the fence dry out. You can use a restore your fence to speed things up or just wait a day or so, depending on the humidity and weather.

Step 6: Take preventative measures

You’ve done the hard work of removing the algae and mold, so now it’s time to prevent it from coming back using the methods mentioned above. 

How To Tell If Your Fence Needs to be Repaired or Replaced

If the algae or mold has gotten out of hand, it’s very likely that parts of your fence need to be repaired or replaced. The most common effect of algae is wet rot, but there are other things to inspect on your fence. 

Signs of Damage on Fence

  • A musty or damp smell on the fence
  • Rotting and decaying panels or poles
  • Spongey wood that’s soft to the touch
  • Splintering or splitting wood
  • Cracks and holes
  • Darker areas
  • Warping slats or posts

If your damage seems more severe than the symptoms above, they may be signs that you need to consider a fencing repair service instead of just a simple algae problem.

Repairing or Replacing Your Damaged Fence

There are plenty of ways to repair or replace your fence, but if you don’t want to DIY it, you can call a professional fencing company to take of it for you. They will thoroughly inspect your fence and come up with a solution that’s fit for the specific damage you’re facing. It’s important to take care of a problem as soon as you notice it to prevent the problem from getting worse or the rest of the fence from becoming damaged.

Close up of damaged wooden fence, rotted at bottom

Having a green fence isn’t just unsightly, it can cause problems down the road when left untreated. Green algae can appear on wood fences and vinyl fences alike, and the effects of it will differ between the two types. Luckily there are plenty of relatively simple ways to get rid of and prevent the green algae and mold, like the tips mentioned in this post.