Our bushes are probably 30 years old, and they have always done well. This spring we had very few flowers. Now we notice the leaves on 3 of the 4 bushes starting to hang limp. We have had enough rain, so it is not drought. Do not see any insects on the leaves. Can you help us?
Your Lilac could be suffering from Lilac Bacterial Blight.
Here are some links with more information.