lilacs have white powder on the stems. What can I do.

Question

I have never had this before. On the leafs but not on the stems. What can I do?

Answer 1

If you don't think it looks like powdery mildew, it may be scale, which is common with lilacs. This article tells how to deal with it.

https://www.gardeningknowhow.com/ornamental/shrubs/lilac/common-lilac-problems.htm