Oak trees

[Valerie]

I have some oak trees that are growing something that looks like a fungus on all the branches and trunk. It is green/grey. Is this a fungus? Do I need to do something with it? I don't want the trees to die.

 

[John Paul Sanborn]

Sounds more like lichen (Lie-ken) an algea, fungae symbiote that lives on all flat surfaces. If is usualy not a problem to a tree, unless it gets so thick the tree cannot asparate. You will find it on rocks, shingles anywhere it is moist and dark.

here is a picture of one type

from this Norweigen University site
http://www.toyen.uio.no/botanisk/lavherb.htm

 

[Valerie]

The picture you sent looks like what is growing on my trees. Some of it is getting rather thick. Is there something I can do to get rid of it before it does kill my trees?

 

[John Paul Sanborn]

It probibly won't but there ar copper solutions that can be sprayed on the colonies, these can stain concrete and paint. Dilute bleach will work too, but may discolor the bark.