Moss on bark

[DMAW]

I have a mature Sugar Maple and a Mountain Ash in a sheltered west facing back yard. Both trees have moss (green) growing on the south side of the stem and branches through out the crown.
Should I be concered about the health of these trees?

 

[DMAW]

Thanks - that's good news. These trees are very important to us.

 

[Treeman14]

Au contrare, mon frere. Moss always grows on the NORTH side of the trunk. Everyone knows this. Those trees need to be turned as soon as possible to avoid irreparable damage to their bark.













I'm kidding. They're fine. Moss is not a problem.

 

[Guy Meilleur]

Are you sure it's just moss? Some gree growths are good, some are neutral, like moss, and some are harmful. Want to post a picture?