I have a young (approx. 6-7 yr)Silver Maple tree that has developed gray spots on the bark of the entire tree. It seems to be healthy though. Does it have a problem, or is this normal? These spots became very noticable last summer. The bark on the tree is not damaged anywhere or blistered. The spots are also on the new growth this year.

I would appreciate any help you could offer to diagnose my tree.
Thank You.

Reply to post by Terri Bayne, on March 30, 2000 at 23:55:04:

Terri
I have often seen a sooty colored surface mold develop on these trees, especially in wet years. It shows up very well on the light colored bark. Can you rub the gray spots off? I don't know of many diseases that bother Silver Maple. If your tree or a neighboring tree has aphids, the sooty mold will grow profusely on the honey dew that they secrete.
Hope this helps. I don't think I would worry as long as everything else seems okay.
Bob

Reply to post by Terri Bayne, on March 30, 2000 at 23:55:04:

WE often see various algae or lichens growing on tree bark, especially shady or moist areas. Usually these are of little concern, as they don't harm the tree. Discolored areas can also be the result of seeping fluids from the tree, either from cracks in the bark (twisting from wind, hail damage, freeze cracks, etc) or from insects boring through the bark.

For a young silver maple, there is probably not much to worry about. You can find a local arborist to check it for you. Look for an ISA Certified Arborist in your local directory, or check the International Society of Arboriculture web site to find one near you:
http://www.isa–arbor.com

Reply to post by Bob Underwood, on March 30, 2000 at 23:55:04:

Thank You for all your help. I appreciate it. Unfortunately, I find that my tree is a Canadian Red Maple. Would this change your diagnosis? I did check the tree again, and the grey spots do rub off. I will keep my eye on it though.

Reply to post by Russ Carlson, on March 30, 2000 at 23:55:04:

Thank You for your information about my tree. Unfortunately I have also discovered that my Silver Maple is really a Canadian Red Maple. I don't know if this has any berring on your solution though. The grey spots do rub off. So I will watch for any other changes.