How to Get Rid of Green Algae on Fences

How to Get Rid of Green Algae on Fences

Green staining on your fence can be a bit of an eyesore, and while it doesn't necessarily harm you, we understand that it can be a nuisance as it makes your garden look dirty. Not only that, but it can also be damaging to your wooden fence as it retains moisture which can lead to rot.

What is making my fence go green?

So what is that green, slimy mess that is ruining your fence?

The cause of the green staining on your fence is most probably green algae. Green algae is a biological microorganism that thrives in damp, shady places, hence why it just loves to reside on wooden garden fences. Rainfall or watering plants causes moisture, and if the water doesn’t dry up then algae spores take up residence and reproduce quickly.

Does green algae harm your fence?

Green algae can be harmful for wooden fences due to the moisture that the algae retains. When wood is affected by excess moisture rot can set in, which ultimately weakens the fence’s structure. If this happens you may have to replace the fence, however, replacing a fence is expensive, annoying and definitely unavoidable!

How do I get rid of green algae on my fence?

The most effective way to remove green algae from your wooden fence is to use a specialist cleaning product such as GK Greener Kleener. These products are specially designed to target the problem, without causing harm to the fence, and keep the spores away for longer.

Greener Kleener is bleach, ammonia, acids, and solvents free which means the product will not interact with any substrate or product that is not living and, unlike most other cleaners, is non-oxidising so will not damage your outdoor fences.

There are household remedies that can be used to remove the green algae but it cannot be certain that they’ll be effective, or that your fence will be unharmed as they often require acid, usually in the form of vinegar.

Removing green algae from fences with GK Greener Kleener in 6 simple steps

1. Put on your protective gear

Biocides will naturally contain chemicals, and these could cause irritation to skin or damage to eyes so always make sure to wear protective gloves and safety glasses to reduce any risk.

2. Dilute the algae remover

The dilution required will depend on the severity of the green algae. GK Greener Kleener requires 2:1 dilution with water for heavy soiling and 3:1 dilution with water for light to medium soiling.

3. Carry out a test

Always carry out a test before applying any product to an entire area. This will ensure compatibility and performance for the perfect end result. We always recommend applying the product on a small, hidden portion of the fence.

4. Apply the product

Make sure your fence is dry before you apply the product. Use a soft brush to remove any excess algae. Then apply the GK Greener Kleener with a brush or a spray. Give the product time to work; we recommend leaving it on overnight.

5. Wash the product away

Once the product has worked, wash it away with water, using a soft bristle brush if necessary. The product has a pH of 6 which is basically neutral so don’t worry about the effects on your garden.

6. Repeat the Process

In order to stop the algae from returning, we would advise implementing a cleaning schedule. Depending on the severity of the problem, repeat the process every 6 - 12 months.

Can I remove green algae from my fence with vinegar?

If you would prefer a household solution for removing green algae from your wooden fence, then a mixture of vinegar or bleach with water will work. However, it is important to note that these methods will not be as effective as an algae remover product, and they may cause damage to the wood.

Mix 1 part white wine vinegar with 1 part water to create a solution and apply to the fence. Leave it for 15 minutes then scrub the fence with a brush and wash away with water.

If using bleach, mix 1 part bleach with 4 parts water to create a solution and apply it to the fence. Leave it for 10 minutes then scrub the fence with a brush and wash away with water. Be careful because bleach can affect your surrounding garden.

Can I use a jet washer to remove algae from my fence?

For less severe green algae staining, a jet washer may be able to remove it. Make sure you don’t use too strong a setting as the pressure of the water could damage the fence!


To summarise, the most effective way to get rid of green algae from your fence is to use a specialist algae remover cleaning product such as GK Greener Kleener. This specially designed formula not only removes algae, but helps to protect your fence for longer. It will not damage the wooden fence or harm the surrounding garden once it is washed away.