WHAT TO DO ABOUT LICHEN ON MY SHRUBS AND TREES
First, in doing some research for this blog, I found writing this blog more educational for me than I originally thought it would be. Over the years I have talked to many customers who wanted to know what was this grey looking barnacles growing on their dogwood trees or on their azalea plants. And, would it kill their plants?
Like with most anything in life, education and knowledge is the key to understanding lichen and their existence on our beloved trees and shrubs.
Here is a little biology lesson for you and for me:
Lichen is an unusual organism that is referred to as symbiotic between different organisms. Lichens are composed of a fungus (the body of the lichen) and algae (the part that photosynthesizes food for the fungus), living together in the same body. Lichens grow in a range of colors, from bright to grayish green. They are not parasitic or harmful to the plant. Lichen is not attributed to being the cause of poor health on any plant. Typically, less vigorous plants and plants with declining growth due to lack of light, poor conditions, and health are susceptible to lichen growth.
The number one question that I get from customers all the time. “My tree is dying!!! It has all of these greenish-gray growths on the trunks and branches. What is this disease and can I save my tree?” The bad news with my advice to these customers is that lichens are not the reason for the tree to be dying. When lichens are found growing on trees or shrubs, it may simply be a sign that a plant is naturally slow growing, such as a dogwood or Japanese maple, or that it is an older plant that is not growing at a vigorous rate. Lichens do not harm the plants they grow upon, but often plants that are struggling will be covered in them. When lichens are found growing prolifically on a plant that also has lots of dead twigs and branches it is usually a sign that something more serious is wrong. Lichen is rarely found on healthy, fast growing shrubs and trees because they are always shedding bark, making it difficult for lichen to attach. As I stated earlier, if you have a tree or shrub that now has lichen, and this has been accompanied by loss of leaves and dying stems, there is a very good chance your plant is not healthy.
WHAT TO DO ABOUT LICHEN?
Although there are no products listed to specifically kill lichen on shrubs and trees, spraying the lichen with COPPER FUNGICIDE can kill the fungal portion of lichen. Ultimately, the real question is why is the shrub or tree declining? We at The Great Big Greenhouse & Meadows Farms Nurseries are always here to help diagnose and discover what the cause could be. However, if the tree looks perfectly healthy and the lichen is on its trunk, there is generally no reason to be concerned. In my opinion, this lichen is just adding character to the bark of the host plant.