I have a 15-20 year old maple, which has lost most of its leaves and looks sickly (this began early summer). The branches are covered in gray-ish discolored spots, and I noticed that there is a blue-ish green colored circular growth on the surface of the bark all over the trunk and branches (not sure if that is common for maples, but I didn't notice these on any of our other Maples (this is the middle of 3 Maples, all 20 feet away from each other). How do I determine the cause of the distress?

Hello Abby: Those gray-ish spots are very likely Lichen moss and are just using the bark as a place to live and not causing any harm to the tree. There a number of foliar diseases and enviornmental stresses that can cause a tree to loss it's leaves. Additionally, there can be vascular diseases that will cause similar symptoms. The foliar diseases and environmental stresses can be mild to severe depending on the growing season. Vascular diseases are particularly bad, as they will eventually cause death. You can submit samples to the University of Illinois Plant Clinic to determine the cause of your trees decline. The web site to obtain the specimen date forms and how to properly send the sample. The web site is: http://plantclinic.cropsci.illinois.edu/index.html

You can cut and past this link in your web brower.

Sincerely, Richard Hentschel