Moss On Your Oak Tree? Here’s The Cause And How To Fix It

Growing trees can be one of the most rewarding things! You may have wondered at some point, “just what the heck is that green fuzzy stuff growing on the outside of my oak tree?” Well, it’s moss, and there’s a few reasons why it’s there.

Moss grows on wet trees and branches out of direct sunlight because it can only grow in moist areas with moderate to low light, as moss spores require water to flourish. If you have moss on your oak tree, it most likely isn’t getting enough sunlight and is in a damp environment.

Read on to learn more about moss, how you can identify it, remove it, and more!

Basics Of Moss Growing On Oak Trees

Moss has pretty basic conditions needed to grow. These conditions are all pertinent to it maintaining life and reproducing. Moss needs both moist and low light conditions.

Moisture is probably the biggest key to moss growth, as moss needs water to reproduce. In addition, having structures such as branches also can increase the chances of moss growth. 

Moss Reproduction

As mentioned, moss needs water (and low light conditions) to reproduce. It creates spores through natural processes, which require water to happen. Without the presence of water, most of these processes occur at lower rates or not at all.

These spores are then released and fly in the wind until they stick to other surfaces (such as rooftops or the sides of trees.)

When the spores attach to other surfaces, they often remain dormant. If they are in the presence of water for a prolonged period, the spores become active and divide on a cellular level, to create new moss. 

Is Moss Safe to Grow On Trees? 

To answer briefly, yes. In most cases, moss is safe to grow on trees as it is not parasitic. However, extreme and excessive moss growth on oak trees can eventually cause tree damage.

This susceptibility to damage is mainly because of the weight. Since moss is usually wet or damp, it is very heavy in large amounts.

When trees have lots of wet moss on their delicate branches, those branches are usually more sensitive to wind and storm damage. This is a good thing to think about when you are controlling moss growth on trees. 

What Does Moss Growth On Oak Trees Indicate? 

Moss growth on trees can indicate a few things. Drawing on basic information, if moss is growing on your oak trees, you can assume your tree is commonly damp and somewhat in the shade. 

Along with moisture and light, moss growth on your oak tree can also show its current health. While moss growth does not harm your tree, it could be a sign that your oak tree has another deeper issue or has taken damage to its outside bark.

This is because when bark peels off of trees, it leaves the perfect area to promote moss growth. In most cases, peeling bark (at least in most oaks) can be a sign of damage or underlying issue, meaning moss is a great indicator of pre-existing tree health. 

Do I Need to Remove Moss From My Oak Trees? 

Due to the nature of moss growth, removing most mosses from your oak trees is purely up to preference. Some people think trees look great with moss and leave it on, while others see it as an eyesore, and remove it.

Since the moss does not harm the tree on its own, removing should be mostly up to how you like the look of it on your tree. 

Removing Moss From Oak Trees

Excessive moss growth on delicate branches can pose a risk for the branch breaking off due to stress. This means you may need to remove moss when it is on small branches to avoid tree damage and safety issues. 

How to Remove Moss From Oak Trees

While it may seem like an alien task, removing moss is simple. For most mosses that grow on oak trees, you can pull it off the bark gently, causing little to no damage to your trees. 

While moss technically makes ‘roots’, it mainly uses them for structural support, simply attaching gently to whatever they are sitting on. This means you can normally just grab the moss and pull it off.

Make sure to wear gloves and a long sleeved t-shirt when peeling off the moss! You can also use a light brush with some water to clean your oak tree’s bark to get rid of the residual moss.

Mosses vs. Lichens 

One important thing to note is the difference between mosses and lichens. Most times, people can quickly misidentify lichens for mosses.

Lichens are lighter on trees and can appear dryer and crusted closer to the surface of the bark. Lichens are a symbiotic relationship between fungus and algae.

On the other hand, moss is usually wetter in appearance, and has more of a 3D structure, coming a fair bit off of the tree. 

Dangers Of Misidentifying Moss And Lichens 

The primary danger of misidentifying moss and lichens comes along if you remove them. Moss is fairly easy to remove and causes little to no damage to your tree. Lichens, however, can do more damage than good. 

Removing lichens can mainly cause damage by ripping off layers of bark with them, leaving bits of the tree’s soft inner core open. Leaving large patches of open tree can leave your oak susceptible to damages such as pests and long term issues.

What Type Of Moss Is Growing On My Oak Tree?

So depending on your environment, there are a few different types of moss that will grow on your oak tree.

In general, three types of moss tend to grow on oak trees. These mosses include Spanish moss, ball moss, and common moss. 

While it may seem arbitrary to identify the type of moss growing on your tree, it can help with removal and control. Different mosses have different growth patterns and reproduction cycles. 

Spanish Moss

Spanish moss is a unique moss, often misidentified as a lichen or algae. In a way, Spanish moss almost looks akin to Halloween decorations, hanging off of trees rather than sticking to them closely. 

Spanish moss is usually a light greenish-white, hanging in festoons off of tree (such as oak) branches. Spanish moss is often associated with trees, such as oaks growing in the south (such as Texas, Arkansas, etc.)

If you’re noticing this is the type of moss you have, take a look at our guide on what to do if you have Spanish moss on your oak tree!

Ball Moss

Ball moss is one of the most easily identifiable mosses. Ball moss grows on the side of trees in the shape of little spheres, similar to sea urchins. During full growth, they can become the size of a tennis ball/softball, normally in a dark to light green color.

When the moss has reached maturity or is dried out (as it is commonly seen), it can appear brown or light tan, with almost sharp protrusions. 

Ball moss is a very common species of moss to see in the south. It is especially common to see growing on the sides and branches of trees in the oak.

You can read our full guide on what to do if you have ball moss on your oak tree here!

Common Moss

According to most sources, “common moss” is not a widely identified species. In reality, “common moss” refers to a group of mosses commonly seen across the globe (found in a variety of locations, in high populations). 

Common moss looks like the picturesque moss we often see in movies: in pillowy green blankets covering objects. This can be seen hugging tightly on the sides of oak trees or simply around their branches. 

Can You Put Moss On Your Oak Trees? 

In short, yes, you can put moss on your oak trees. Most mosses can easily transplant onto surfaces under the correct conditions.

The most common moss to transplant is Spanish moss, however, others can be transplanted as well. In addition, simply creating correct conditions for moss growth can also improve the chances of moss growing naturally.

Spanish moss is actually quite beautiful!

There are many ways to transplant or improve the chances of getting moss, so take any tips with a grain of salt, as outside factors such as climate and tree type can also impact moss growth. 

Best Conditions For Moss Growth

As mentioned, you need the correct conditions to get moss to grow. These required conditions include having a semi-shady location and having frequently moist surfaces for moss to grow off of.

You can create some of these conditions on your own if you want to have moss grow on specific trees. To create semi-shady areas, you can try planting trees, other larger shrubs, and plants, or try planting the tree you want moss on in an already shady location.

As for creating damp conditions, you can also somewhat achieve this by planting strategically. This means densely planting high humidity plants that retain moisture (so the area stays somewhat damp and humid). If this is too much for you, you could also experiment with hand watering or misting the tree frequently to keep it damp as well. 

Encouraging Growth 

Instead of physically putting moss on your tree, you could also create the correct conditions for it to grow. Doing so will increase the chances of nearby moss naturally throwing spores that successfully stick and grow on your tree. 

To get moss to grow naturally (without direct transplanting or propagating), your tree has to be near existing moss. This is because moss replicates by throwing spores that fly in the wind, meaning it can only replicate for a certain distance away. 

Direct Transplanting 

Direct transplanting is another method for putting moss on a specific tree in your yard. To directly transplant moss, you, of course, need a patch or colony of preexisting moss in a healthy state. It is important the moss you are moving is healthy. If it is sick, it could simply die, or even transmit something to your trees. 

Most people say to direct transplant, you can simply take the moss from one location, and move it to your desired tree. As long as the tree has the correct conditions, the moss should be able to regrow successfully on the tree and multiply.

Similar to planting moss for fish tanks, some people also recommend tying the moss to the tree with fishing line. This is especially helpful if you want your moss to be in positions where it can easily fall off of the tree because of gravity. 

Does Moss On Oak Trees Cause Bugs? 

To answer plainly, it depends. Bugs are usually attracted to moisture, soil, food sources, etc. This means healthy moss (which is usually damp or wet), can be attractive to certain insects. On the other hand, if you have more of a dry hanging moss (such as Spanish moss), the chance of insect infestation is significantly lowered. 

Moss On Trees

As mentioned, in most cases, having moss on trees will not attract too many (harmful) bugs. Destructive bugs, like termites, are not normally attracted to moss (just the tree itself). This means, in most cases, moss won’t attract bugs dangerous to the tree itself. 

While moss will not attract tree-harmful bugs, it is important to know what bugs moss attracts, and how those bugs can affect the rest of your yard. 

Negative Bugs Attracted To Moss

Moss can have the effect of attracting some bugs capable of yard damage. Some common bugs attracted to moss include springtails, thrips, aphids, spider mites, etc.

If your moss or oak tree are a part of a garden (with other vascular plants), the attraction of these bugs could be an issue. They can quickly and easily cause a lot of damage to regular plants you would find in the average home garden!

Conclusion:

In the end, moss growth can seem like a very confusing topic, especially when you introduce the idea of different mosses, and how their reproductive cycles change depending on what surfaces they are growing on. In most cases, moss will tend to (and often requires) frequently damp surfaces and medium-to-shady light conditions to grow. 

Moss is usually safe when growing on trees, so there is no need to worry about it causing damage or sucking nutrients from your oaks. It can be used as an easy indicator of tree health, and if you want to remove moss from your oak, it is a simple and easy process to complete!

There are a few different mosses that can grow on oak trees, and they all have their unique looks, reproductive cycles, benefits, etc. If you want moss to grow on a specific tree, there are ways for you to create the correct conditions for it to grow, or even for you to transplant it onto a specific tree. 

In the end, moss is a pretty interesting plant you can use to add a lot of character to your oak trees. With this, take some time to think about the moss growth in your garden, what it means, why it is caused, and what you personally want to do about it! 

References

Angeles, M. A. 600 E. P. A. P., & Us, W. 98362 P.-3. C. (n.d.). Mosses – Olympic National Park (U.S. National Park Service). Www.nps.gov.

MossBasicsText. (n.d.). Bryophytes.science.oregonstate.edu.

Physical control of moss on trees. (n.d.). Bryophytes.science.oregonstate.edu. Retrieved April 14, 2022.

Living in the Land of Mosses. (2016, May 24). Pacific Northwest Pest Management Handbooks.

Lichens | University of Maryland Extension. (n.d.). Extension.umd.edu.