Green algae, often seen as an unwelcome visitor, can be a nuisance when it appears on your wooden fence. Not only it does make your garden look unkempt but also can slowly damage the wood over time. In this article, we will delve into the importance of removing green algae from your fence and provide you with a few effective methods to get rid of them.

Background and Significance

Green algae are microscopic organisms that thrive in damp and shady environments. They reproduce quickly, covering up wooden fences with a layer of slimy, green film. While green algae may not pose any serious risks to one's health, it can make the fence look unattractive and even adversely affect the wood by retaining moisture, causing rot, and weakening the fence's structure.

Causes and Prevention

Green algae favour damp and shady areas, and poorly drained soil or areas with poor air circulation can encourage their growth. Preventing the onset of green algae on your fence may include regular maintenance and some straightforward practices:

  • Prune overhanging trees or shrubs to ensure the area remains well-lit, which helps to reduce dampness.
  • Ensure proper drainage around your fence, avoiding water pooling near the fence's base.
  • Paint or seal wooden fences to protect the wood from moisture, making it less conducive for algae growth.

Methods to Remove Green Algae

1. Scrubbing and Rinsing

A simple and cost-effective way to remove green algae is by scrubbing the affected area with a bristle brush. Mix a solution of water and a gentle detergent, like washing-up liquid, and use it to scrub the algae. Once finished, thoroughly rinse the area with water from a garden hose.

2. Using Algae Removers

Commercial algae removers are specifically designed to eradicate green algae and can be easily found at most garden centres or online retailers. When using these products, follow the manufacturer's instructions carefully, as overuse or incorrect application can damage your fence. After applying the algae remover, rinse the fence thoroughly with water.

3. Power Washing

Power washing can be an effective method for removing green algae, but it must be done with caution to avoid damaging the wood. Use a wide spray nozzle and adjust the pressure as needed – start with low pressure and increase it gradually if necessary. Keep a safe distance from the fence when power washing to prevent damage to the wood. It's worth noting that power washing may strip away paint or protective coatings, so plan to reapply them once the fence is clean and fully dried.


Green algae on wooden fences can be unsightly and, if not addressed, lead to wood deterioration. It is important to maintain your fence regularly to prevent green algae growth, and when it does appear, take swift action to remove it. By following the methods outlined in this article, you can restore the natural beauty of your fence and maintain its structural integrity. Moreover, a well-maintained wooden fence can serve as the perfect backdrop for your blooming garden, allowing everything in your outdoor space to thrive.