Learn / Ask The Landscape Professional
I have this green fungus-looking stuff on the side of my large trees. How do I get rid of it?
You have Lichen growing on your trees. It
is completely harmless and there is no need
to get rid of it. Lichen is a unique organism
because it's not just a fungus, but an alga as
well that lives with the fungus symbiotically
(when two different kinds of living things
live together and depend on each other).
The fungus part of lichen collects moisture
which the alga needs and the alga creates
food made from the energy of the sun for
the fungus. Lichen is found in many places
like on trees and rocks; in gardens they look
wonderful on landscape rocks. Lichens are
completely harmless to trees and although
they are attached to the tree bark by "rhizines"
which are hair-like roots, they do not penetrate
deeply enough to cause any concerns. Lichen
grows slowly and likes undisturbed surfaces, so you won't see it on species of
trees that shed their bark frequently.
Different forms of lichen have been all over the world for centuries, including
the Artic and Antarctica. There are more than 15,000 types of lichen and
estimates run as high as 6% of the earth surface is covered by lichen. Around
the world, as far back as Roman times, lichens were used as dyes for fabric and
in healing ointments. Lichens have even been found inside Egyptian mummies
from 1500BC! Since the 1300's, lichens have been as the main source of dyes
used in litmus paper, a paper testing strip used to determine pH. Today, they
are used in perfumes and in dried flower arrangements as well as for miniature
plant representations for model railroads.
Lichen will only grow is areas where the atmosphere is clean, so it's a good
sign and you can be happy that you have them growing on your property!
View As PDF
To view a PDF of this article, please
About Linda Lillie
Linda K. Lillie is the President of Sprigs & Twigs, Inc, the premier
landscape design and maintenance, tree care, lawn care, stonework, and carpentry
service provider in southeastern Connecticut since 1997. She is a graduate of
Connecticut College in Botany, a Connecticut Master Gardener and a national
award winning landscape designer for her landscape design and landscape installation work.