Diseased tree?

Asked October 26, 2013, 6:55 PM EDT

Hello - we have a few trees in our backyard that appear to have a problem. During the summer, there seemed to be a bit of sticky sap on our patio - maybe from these trees. The leaves were sticky and appeared to have something on them. Then, they discolored instead of having a normal fall leaf color. I've attached a photo and can send more, if needed. Can you help us to identify the type of tree this is, and what its problem is? Thank you! Brandi

Washington County Oregon tree problem discolored leaves

1 Response

Whenever a tree or shrub is dripping a sticky material, it’s very likely that insects are feeding on the leaves. More often than not, those insects are aphids, small pear-shaped fellows about 1/8-inch long that suck plant sap. In such instances, a harsh water spray Is adequate treatment; repeat as needed.

It’s difficult to ID a tree with only one leaf. But my best guess is quaking aspen, Populous tremuloides. (Please compare your tree with the images here http://oregonstate.edu/dept/ldplants/3plants.htm#potre. Aspens are deciduous (lose their leaves for the winter) and, in our region, are commonly affected by leaf disease. Nothing can be done at this time other than to collect and discard the affected leaves which have fallen.