I have a 25' cottonwood. It has been spreyedmutiple times with compost tea we have had plenty of rain here in Alpine (6" this year). Now I have found green nodular growths on the leaves . Most are the size of my thumb end. Some are uniform and some are quite irregular in shape. I haven't cut one open yet, but I will this weekend. Any idea if this is a probem? I looked through the Texas Bug book and didn't see any thing. The Cotonwood borer didn't seem right.

Those are leaf galls. If the tree is in a place where it is important to stay, appply the Sick Tree Treatment.