Shriveling, curling leaves on lilacs
Hi all. This is my first post here. I love lilacs and have planted them successfully at every place I've ever lived...until now. We've lived here for 6 years and every lilac I plant (now totaling 4) goes in great, blooms great, then the leaves get all curled and shriveled and there is very little new growth all summer long. The leaves drop in the fall and the next spring, the leaves emerge perfectly, the plants bloom beautifully, then the leaves shrivel up again. I've tried 2 Miss Kims and two traditional lilacs. They are planted in different spots in my 5 acre yard, so it is not something local to the specific planting spot. They are all in full sun. The soil here is pretty clay-ey and I did not amend it much - the Miss Kims got new topsoil in the beds they are in, but the other two I think are planted right in the clay. I'm not entirely sure what powdery mildew looks like, but I don't see anything on the leaves at all - they look fine, just curled up. And I thought Miss Kims weren't supposed to get mildew anyhow?
Any clue what is going on? They look so pathetic right now I'm tempted to tear them out!