How to Get Rid of Green Algae on Fences

Green staining on your fence can be a bit of an eyesore, making it an unwelcome visitor that you will want to remove. While it doesn't cause any harm to you, we understand that it can be a nuisance as it makes your garden look dirty and unkempt. Not only that, but it can also be damaging to your wooden fence as algae retains moisture which can sadly lead to rot over time.

In this article we will be exploring what this green growth is, how to remove it from your fence, and what measures you can put in place to prevent its regrowth moving forward.

What is causing my fence to go green?

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

The cause of the green staining on your fence and other wooden structures within your garden is most commonly green algae. Green algae is a biological microorganism that thrives in damp, shady places, making your wooden garden fence the perfect place to set up residence. Unfortunately, once green algae has found its home, it will continue to spread and can start to become a very noticeable, unpleasant problem.

Why is there green algae on my fence?

In order to remove green algae effectively and prevent it from returning, we must first understand what is causing its appearance to begin with. Algae spores are always present within the environment, but there are a few conditions that are required for them to thrive and grow. The key contributing factors to algae growth are moisture, shade, and nutrients. Wooden garden fences are often placed near plants and succumb to various weather elements, all of which will provide a nutrient-rich playground for them to grow.

Watering plants regularly, combined with the seemingly ever-present rainfall in Britain, ensures that your garden fence remains damp for the majority of the year. This provides the ideal environment for these algae spores to spread and flourish.

Combine this with plant matter, dust and soil, and you have created the perfect breeding ground for green algae.

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 avoidable!

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 algae remover product such as GK Greener Kleener. This product has been specially developed to directly target the problem of green algae and other biological growth, without causing any harm to the fence. The specialist formula has also been expertly designed to add an extra level of protection to your fence, keeping 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.

The product is also more environmentally friendly than other commercial algae removers on the market. It boasts a virtually neutral pH of 6, and once it has dried, it will not pose any risk to plants or animals.

While there are household remedies that can be used to remove the green algae, it cannot be certain that they’ll be effective, or that your fence will be unharmed as they often require acid or bleach, which can be corrosive to wood.

Removing green algae from fences with GK Greener Kleener 

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. Prepare the fence

Make sure your fence is dry before you apply the product. Use a soft brush to remove any excess algae so you don't damage the wood.

5. Apply the product

Apply the GK Greener Kleener with a brush or garden sprayer. Give the product time to work; we recommend leaving it on overnight.

6. Leave the product to work

Once the product has worked, leave it to evaporate naturally with cycles of sun and rain. The product has a pH of 6 which is basically neutral so don’t worry about the effects on your garden.

7. 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.

8. Enjoy the magic

Greener Kleener is designed to evaporate naturally and will continue to provide lasting protection for months.

Other methods to remove green algae from fences

Let's explore some other methods which can successfully kill algae. Please note that each method will its own advantages and disadvantages.

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 white vinegar and water is an effective solution. This is a more eco-friendly option compared to some alternative methods, however, it is important to note that while this method will remove the algae, it will not provide the same lasting protection as an algae remover product.

The first step when cleaning algae is to put on the appropriate protective gear such as gloves and an eye mask or goggles to prevent debris or cleaning agents from getting into your eyes or irritating your skin.

Using a soft brush or broom, gently remove as much loose or bulky growth as possible. Do not use a hard brush as this could cause some damage to the underlying surface and must be avoided to prevent algae regrowth from setting into small cracks.

To remove green algae from a fence with white vinegar, mix 1 part white vinegar with 2 parts water to create a solution. Apply this liberally to the fence, making sure that all the algae is properly soaked. Leave it to work for 15 minutes then scrub the fence with a soft brush and rinse the fence thoroughly with clean water from a hose.

This method will provide some lasting protection against regrowth as the acid makes the environment unpleasant for algae spores.

Can I use bleach to remove algae from my fence?

Bleach is another method that can effectively kill algae.

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 when using this method because bleach can harm your surrounding garden and wildlife.

Can I use a jet washer/pressure 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!

Removing green algae from a fence with boiling water

You can also remove green algae from your garden fence by pouring boiling water directly onto the algae growth. Extra precaution must be taken if using this method to prevent any harm to yourself from burns.

While this method is safe for the environment due to the absence of chemicals, hot water could scold plant roots or leaves, and may harm any other beneficial wildlife including insects.

Removing green algae from a fence with copper wire

For a more permanent solution, installing some copper wire along the top of your fence is an excellent solution that can prevent the reappearance of algae. This happens due to the ions within the copper. As rainfall cascades over the copper, these ions are released, creating a toxic environment for algae spores and preventing growth.

This method can be more costly and will require some setup.

Preventing algae regrowth on fences

Once you have removed green algae from your fence, you will want to prevent it from returning. Here are some methods that will effectively prevent or limit regrowth.

Apply a wood sealer 

Applying a waterproof wood sealer to your fence is a great way to protect it from algae regrowth, as well as limiting the effects of weathering such as fading. We supply an effective wood sealer, GK Invisible Wood Sealer. 

GK Invisible Wood Sealer is a water-based sealing solution designed specifically for use with decking, fencing, timber and other wood structures. This ready-to-use sealer penetrates deep into wood, creating a robust defence against moisture and rot, while its algae-repelling formula keeps your wood surfaces pristine. The invisible sealant layer is both UVA resistant and highly resistant to wear.

Keep your fence dry

A more obvious, though challenging, way to prevent algae regrowth on your fence is to keep the fence as dry as possible. This can very difficult in countries such as the UK due to the amount of rainfall, but steps can be taken to make a significant difference.

Two natural deterrents to algae growth are sunlight and air flow, so increasing the fence's exposure to these two things will be beneficial. To achieve this, trim back any plants and branches, or remove any trellis so that the fence has clear access to both sun and air.

Maintain your fence regularly

Keep your fence clean by washing it with a hose. This is especially important if you can see early formation of algae staining. If using a commercial cleaner, use regular inspections as a way to indicate when it is time to reapply the solution.

Taking these preemptive measures will prevent the reappearance of algae, keep your fence looking pristine, and maintain its structural integrity.

About GK

At GK, we are passionate about outdoor cleaning. All our products have been developed with professionals to ensure a thorough clean without the expense of hiring a professional cleaner. We understand the importance of creating eco-friendly formulas that protect your investments while having little to no impact on the surrounding environment, which is why our cleaning solutions boast neutral pH values. 

All our products ensure an effective cleaning process every time, so that you can enjoy your outdoor spaces with confidence.

Summary

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 has dried.