We have what we think is an ash tree and sometimes in spring and summer, it puts out a white to greyish sticky substance and the leaves curl. The substance falls on everything in the surrounding area. Do you know what this could be and can it be prevented?
Ash Tree Problem
I have an ash tree that did the same thing. It turned out to be tiny worms that rolled up in the leaves, the tree dripped gooey stuff and had the same thing with stuff falling on the ground. The tree looked sick. I got some Bayer Tree and Shrub granules and applied them around the base of the tree as the label instructed. Soon things cleared up. The following year I did the same application early in the spring so as to get ahead of the pests. It worked too and the tree had no problems. I do that same application each early spring now and the problems have not come back. There is a systemic insecticide in the Bayer product that keeps things under control and it feeds the tree too.