What is the blue-green moss or mold on tree trunks?

[Gus]

I mentioned this in my other post, but I thought that I should address it separately.

We recently moved into a house that has a lot of ash trees around it. I have noticed that a lot of the trees have a blue-green colored moss or mold growing on the trunks and branches. We see this not just on our trees but in a lot of the trees in the neighborhood. Is this an indication that the trees are in decline? Should we be concerned - can it hurt the trees?

Your advice is appreciated.

 

[Jay Banks]

If these are lichens then they will not harm the tree. Lichens are a moss/alga hybrid with a symbiotic relationship toward each other. They live together for the benefit of the other.

You will find these on alot of trees and stones.

 

[Gus]

Jay,

Yes, that is very likely what they are. Maybe all of the rain we have been having is making them more noticeable.

Just wanted to make sure. Thanks for the responses.

 

[Newfie]

Hey Gus,

As I always learned it, lichens were a good thing, in that they are a sign of good air quality. I suppose none of air is "quality" anymore, but at least yours is good enough to support lichen as opposed to not. Of course I may have just been speaking out of my a$#. I'm sure I will be corrected if this is the case.

 

[tshanefreeman]

If you had the choice of living in an air conditioned/properly heated home or in a tent all year round, which would you choose?

Of course you would most-likely choose to live in the first.

Well moss and lichens are the opposite. They thrive in high humidity and warm temperatures. I must admit that I am not really familiar with the Kentucky climate, however, about a month ago I got back from a trip to the Milwaukee/Chicago area and I couldn't get over the mass quantities of moss growing and thriving on the trunks of trees. Due to the increase humidity from the lake, the conditions were perfect for vigorous growth. This was a real shock to my eyes, considering the relatively dry climate of Killarney, Manitoba, Canada, which is my home. For here you can actually see the true color of the bark and not have to worry about washing moss stains out of your pants at the end of a days work.

This growth that you are describing is nothing to worry about. Nature created this symbiotic relationship thousands upon thousands of years ago. I am positive that if the various types of moss haven't killed off all of the trees yet, it most-likely will not!

Shane Freeman
"...insight from North of the border!"

PS: You are probably right in that it is more noticable now with the damp conditions. The moss will be thriving off of the increased moisture and humidity, thus greening up. Also the moss will be showered of any dust that would dull the beautiful green color of chlorophyll.

Shane Freeman