What is That Moldy Substance Growing on Your Trees?

Are you noticing an odd-looking moldy type substance growing on the trunk of branches of your trees? Here in our warm, sunny, humid North and South Carolina climate, we often experience the growth of lichens. While they will not harm your tree or plant itself, lichens will attach themselves to your plants and trees and rob them from receiving proper nutrients. In this article, learn everything you need to know about this unique, unsightly organism, how and why it grows, and what you can do to remove it.

What is Lichen?

Lichens are a complex life form that is the formation of two separate organisms, a fungus, and an alga. The fungus is the dominant partner, giving the lichen most of its characteristics.  There are approximately 3,600 species of lichens across North America.green lichen moss

What Are Fungi?
Fungi are a diverse group of organisms that do not contain chlorophyll or any other means of producing their own food, so they rely on other organisms for nutrition. Fungi are widely known for their role in the decomposition of organic matter. Because they cannot produce their own food, they absorb nutrition from organic substances, including algae, in seeking outside sources of food.

Algae is a diverse group of aquatic organisms capable of producing oxygen through photosynthesis (harvesting light from the sun to produce energy). There are several types of algae, including green, brown, red, and gold. They can survive in saltwater and freshwater on their own.

What Happens When They Partner?
When a fungus associates with an alga to form a lichen, it provides itself with constant access to a source of nourishment. If you find lichens growing on one or more of your trees, the algae are creating food from the sun’s energy giving the fungus the resources it needs to survive.

Where Does Lichen Grow?

In North and South Carolina, along the eastern coastline, our climate is warm and moist. This provides the perfect environment for lichens to grow. Lichens grow on rocks, dead wood, soil, tombstones, or other sunny surfaces. They will also grow on dead twigs and branches. Lichen prefers bright areas with good air circulation, so plants with thin canopies provide excellent growing conditions. Usually, this indicates that something else is wrong with the plant or tree, such as disease or insects, or stress from drought, compacted soil, or flooding.

Why are Lichens Considered Bad?

Lichens are usually an indication that something else is wrong. They are rarely found growing on healthy, fast-growing trees and shrubs because they are always shedding bark, making it too difficult for lichen to attach to them. If loss of leaves or dying stems also accompany the trees or shrub you are spotting lichen on, there is a good chance your plant is not healthy.

Usually, when a tree or shrub is not healthy, it is directly related to the root system. Even though roots live within your soil, they need oxygen to live and grow. Oxygen exists in the ground in the tiny spaces between individual soil particles, but when these spaces are compacted or filled up with water, there is no room left for oxygen. This causes the roots to suffocate. Here in North and South Carolina, this is often the case during hurricane season when we receive an abundance of rain.yellow lichen

Treatment Options for Lichen

Scrub the Bark
One way to treat for lichen on your trees is to scrub the tree’s bark with a soapy solution gently. They typically fall off easily simply by being attached to the bark. Be careful not to clean too hard as you risk damaging the tree’s bark opening it up to pests and diseases.

Lime Sulfur
Lime sulfur can be used to remove lichens from tree bark. It will kill the fungus that makes up half the lichen. Just be careful not to apply the lime sulfur to the roots or leaves of the tree, as this can damage your beloved lawn ornament.

Copper Sulfate
A third way to rid your trees and shrubs of lichen is by using copper sulfate. Like, lime sulfur, copper sulfate sprayed on lichens will kill the fungus side of the organism. Only use copper-sulfate as a treatment for tree lichen in late spring through early fall. It will not be effective in cool weather.

Hire a Professional
Your best option is to hire a tree, and shrub care professional with experience and know-how regarding trees, shrubs, and the local North and South Carolina environment. Fungicides can be applied to help eliminate and prevent the spread of lichen and are typically applied in the late fall.

For All Your Tree and Shrub Care Needs, Contact Impeccable Lawns

At Impeccable Lawns, we understand the different kinds of trees and shrubs we have along the Atlantic coast and the variety of pests, diseases, and fungi growing on our beloved plants. We offer a comprehensive tree and shrub care program that was developed specifically to promote healthy growth and protect your trees from being overtaken by pests and diseases. It also includes a fungicide application specifically to help eliminate and prevent the spread of lichen and other fungi.

As the only local company to treat this devastating fungus, we recommend that you contact us and get started on our tree and shrub care program now. The fungicide application is applied in late fall, so there is no time to wait. Visit our website to contact us online or give us a call today at 910-575-5296.

Did you find the information above useful? Feel free to share it with family and friends. Then check out our other blog articles for more information on all things lawn and landscaping. Don’t forget to visit us on our Facebook page and give us a shout-out!


Oops! We could not locate your form.

Click me for a modal

Contact Us