|My lilac bush is currently in bloom but despite the rain we've had the leaves are curling and some blossoms are turning black and shriveling before they're finished. The bushes are quite old but have never had a problem with them in the past. Is is a disease that could be treated with something? The leaves don't seem to be filling out the bush as much as in past years also. Please advise. The purple bush looks worse than the white one. They are about 8 feet from each other. Thanks for your consideration and help with this problem.
|Lilacs are subject to a number of bacterial and fungal infections and it sounds like this is what has happened during this moist spring. Trim out any of the infected leaves along with any stems that might have lesions on them. Clean your pruner in a solution of one part household bleach to nine parts water in between cuts. Next, prune the top to allow good air circulation, and thin out the base for the same reason. Remove any suckers smaller than a pencil, too. Lilacs do best in full sun with good air circulation, so keep this in mind when landscaping that area. Finally, avoid giving the plant an excess of nitrogen, as this can encourage the problems.