I found this group through a search and thought someone might be able to help me here. I have a white paper birch tree in my yard and this spring it seems to have a fungus (maybe) on the leaves. It is on the underside of the leaves only and is gray in color. It causes the leaves to crinkle and curl. I guess eventually they will fall off. Does anyone know what this might be and what I can do to get rid of it?? Thank you for any help.
Dave

Reply to post by Dave, on May 26, 2002 at 18:53:32:

You may actually have an insect problem on the birch. They are sometimes infected by a leaf aphid. They feed on the lower sides of the leaf, causing the crinkled pattern. If you carefully open the leaf and probe (a finger or tip of a pencil will do) you will see individual aphids, often covered with a white fuzzy material.

If this is the problem, it will probably not harm the tree unless it is extremely infested. control measures are not usually recommended, as it is more of a cosmetic problem, not a health threat.

It might also be some type of powdery mildew, although this does not usually causing the crinkled appearance. If you still are not sure and are concerned about it, find a qualified local arborist, or contact your local Cooperative Extension office. The International Society of Arboriculture maintains a current list of ISA Certified Arborists. The searchable list can be accessed at the ISA Web site, at:
http://www.isa-arbor.com

Reply to post by Russ Carlson, on May 26, 2002 at 18:53:32:

You may need a hand lens to see the aphids. If it's them, a soap spray can smother and kill them non-toxically.
I agree it's usually just cosmetic, but imo it's a sign of the tree's distress that aphids are feeding heavily on it. It is best to get rid of them.


Check the overall condition of the plant and get it in the best shape possible. See www.isa-arbor.com and their consumer info.