Our lilac appears to have some powdery mildew, and other leaves that are brown and splotchy. Some branches have gotten quite bare, and this has been going on since earlier in the summer. My husband cut off some large branches this weekend because he was worried they were diseased, after hearing there was a blight affecting lilacs in the area. Can you please give us any idea what’s going on with our lilac, and if it’s necessary to aggressively prune it? How to we treat whatever is going on? We also noticed the center of the branches that he cut off are dark in the center of the branch. Is this normal? Thank you! Dana in Minneapolis