What Causes Moss to Grow on Trees?

Moss is a resilient plant that can withstand extreme weather conditions. It can grow on many different surfaces, including rocks, buildings, and trees. Moss is beneficial to the environment, and it's also beautiful to look at. But what causes moss to grow on trees, and is it ever harmful? Let's dive into the details and learn if you need to worry about moss growing on your tree.

What Causes Moss to Grow on Trees?

Moss tends to thrive in moist, shady conditions. Since it’s a nonvascular plant, moss absorbs nutrients and water directly into its cells. Trees that aren't exposed to as much sunlight or are growing in damp, cloudy climates are more susceptible to having moss on them. 

The rough exterior of tree bark offers a prime location for moss spores to attach and grow. Environments such as dense forests will have an abundance of moss growing on the ground and on the trees.

Where Does Moss Grow on Trees?

Moss will grow where conditions are ideal. So, it can grow on any spot on a tree, including the sides, branches, and stump. However, where you live may determine which side of the tree has the most moss. For example, if you live in the northern hemisphere, then moss may grow on the north-facing side of trees because it is more shaded. Trees that are located in the southern hemisphere will have more moss growth on the south side.

Moss prefers trees that have deep crevices and rigid bark. Also, moss tends to grow on older trees.

Is Moss Harmful to Trees?

Moss is harmless to trees most of the time. However, excessive overgrowth of moss can add weight to the tree and cause it to be waterlogged. Add in some inclement weather, and there’s more of a risk that the tree will start to lean and sustain damage such as broken branches. 

Moss can also make it more difficult to identify if a tree has a disease or an infestation. Identifying these issues early on is vital if you are trying to save a dying tree.

Should You Remove Moss From a Tree?

Whether you should remove the moss depends on what is best for your tree. Moss benefits the ecosystem and can even assist in protecting the tree's bark from extreme weather conditions and temperatures. However, it can also mask potential problems such as diseases or pests. 

If your tree has an excessive amount of moss and you aren't sure what is best, then you should hire an arborist near you to inspect the tree. They can identify if the tree is healthy and whether removing the moss will benefit the tree.

Light moss growth can be removed by hand. Just make sure to wear gloves. In some cases, a pressure washer may be used to assist in removing moss from a tree. However, you should follow the directions of an arborist to ensure you do it correctly and don't damage the tree.

Tips to Prevent Moss From Growing on Trees

If you notice there is too much moss growing on your trees, you can have it removed and then use various techniques to prevent it from coming back. Here are some key tips to implement to reduce or prevent moss growth:

• Properly prune your trees: Trimming your trees will allow more sunlight to reach various surfaces of the tree and can prevent moss from growing. Moss prefers shady, moist conditions.

• Reduce water intake: In some instances, you may need to water your trees and yard less often. You’ll need to avoid going in the opposite direction and underwatering your trees, but reducing the amount of moisture can help prevent moss growth. 

• Aerate the soil: Pooling water around trees and in your yard can promote moss growth. Aerating the soil can improve soil drainage and prevent standing water. Be careful when aerating around the tree and make sure not to damage its roots.