Hello Fellow Readers,
Last week’s column about removing moss from retaining walls (an idea I don’t favor as stark walls softened by mossy volunteers is magnificent) inspired questions about removing moss and lichen from tree trunks. But there’s no reason to remove it and many reasons to like lichen and moss.
Lichen and Moss do not indicate the tree’s demise.
My dear Curt was concerned about the maple tree near the screened porch adorned with a tapestry of powdery blue lichen interwoven with moss. Rest assured, the presence of lichen and moss does not indicate the tree’s demise. However, you indeed see more of these mysterious organisms in mature forests because of the years they take to develop and thrive, especially so for lichen.
Lichen and moss add protection.
Other opportunistic plants like wisteria, poison ivy vines, and kudzu smother trees, but moss and lichen cause no harm. They’re merely seeking a structure to call home, such as trunks, branches, rocks, even furniture where moisture and shade are plentiful. Living hosts benefit from lichen and moss’s added barrier of protection.
The Magical Mystery of Lichen
According to Texas A&M AgriLife Extension Service, the part-fungi and part-algae or blue-green bacteria of lichen are not a “true species.” The fungal partner relies on the “photosynthetic products provided by the algae or bacteria,” resulting in a resilient combo of algae and fungi “that is practically self-sufficient.”
It often takes years for lichen to create a cover over bark that can live for hundreds of years, giving our beloved maple an old-world charm.
Does moss grow on the north side of the tree?
There’s an old wives’ tale that moss grows on the north side of the tree, which is not valid. Moss often colonizes all around trunks close to the forest floor. It also is found in shady spots of lawns because of the moisture from constant ground evaporation. The slant and fissures of bark are variables, too, where water is slower to drain. Or if the tree is in a thick forest of shade.
Authorities such as Tristan Gooley, author of The Natural Navigator (2010), wouldn’t put the northside folklore in his top-twenty techniques list. Instead, he suggests a compass — which means, of course, learning to use one. Mind-boggling to me; thank goodness for GPS technology.
For those of you that feel these natural fuzzy organisms compete with the beauty of the bark, last week’s water-only power washing technique at a low PSI may work, but only when the tree is dormant after the leaves drop. And be extra careful not to damage the bark, which would encourage pathogens and other opportunistic campers that aren’t self-sufficient or as beautiful as moss and lichen.
Garden Dilemmas? AskMaryStone@gmail.com
Column updated 3/19/22
Link to Episode 12 of the podcast that features Magnificent Moss