Algae on Trees: Should You Be Concerned?

Did you recently take a stroll in your yard and find a mysterious greenish substance covering the bark of your tree? If you feel a twinge of concern, you’re not alone. 

As Clovis’s trusted tree service, we at Cut Rite Tree Service know much about preventing algae on trees. Keep reading as we break down the details for your peace of mind.

What Tree Algae Growth Means

Algae are simple, plant-like organisms that can grow on various surfaces, including tree bark. They don’t have a preference for their home and can thrive in a range of conditions. However, they have a particular fondness for moist, shaded areas. This preference means that if your garden or yard doesn’t get a lot of direct sunlight or tends to hold onto moisture, it might just roll out the welcome mat for organic growths.

Should You Remove Algae on Tree Trunks?

Clearing algae on trees is usually just more for aesthetics than health. These organisms don’t cause direct harm, but they might indicate problems like:

  • Low sunlight: Shady spots can lead to slower growth as trees struggle to photosynthesize effectively. 
  • Inadequate drainage: Does the ground around your trees feel waterlogged? Too much moisture can encourage not only algae but also other potentially more harmful organisms like fungi.
  • Competition for nutrients: While algae itself doesn’t harm a tree’s growth, it can serve as a cover for other, more sinister guests like invasive species that might compete with your tree for vital nutrients.

If your specimen looks healthy and you don’t mind the aesthetic, algae on tree trunks alone isn’t necessarily a cause for alarm. Warning signs like drooping leaves, brittle branches, or a sudden lack of growth merit closer investigation.

Managing Algae on Trees

Do you prefer a cleaner look for your trees? Treating an algae infestation on tree bark is quite straightforward, as it needs little more than a bit of elbow grease and the right ingredients. 

Prepare a solution containing 1/8 cup of white vinegar or chlorine bleach and a gallon of water, then spray it directly onto the affected areas. After allowing it to sit for a few minutes, gently scrub the algae off with a soft brush while taking care not to damage the bark. 

Rinse the area with clean water afterward to wash away any residual solution. For larger trees or more stubborn infestations, spray a solution of copper sulfate (a teaspoon of powder per eight gallons of water) directly onto the algae. 

Consult a Local Arborist for More Help Clearing Algae From Trees

Unless you change the environmental conditions contributing to algae growth, it will likely return over time. Our crew at Cut Rite Tree Service is always here to help you understand and manage the aspects of your garden’s ecosystem. From proactive landscaping to ensuring adequate sunlight and drainage, we can guide you through creating an environment that discourages unwanted organic growths.

Dial 559-320-7723 to address algae on trees, or read more of our blog to learn about the parts of a tree.


We are a locally owned company that prides ourselves in providing the best service possible for the residents of Fresno, Clovis, Madera, Sanger, Folwer, Reedley and the surrounding areas.

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1806 N Temperance
Fresno, CA 93727


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