What can be done to help our elderly lilacs?

Asked June 18, 2015, 10:11 AM EDT

We bought a home a couple years ago that's over 100 years old and there are a couple of lilacs planted along one of the outbuildings. They are quite tall (over 8 feet), the leaves don't start for about 4 feet from the ground, and they are barely producing flowers. Can anything be done to bring them back, or do we need to take them out and replant new ones?

Pine County Minnesota

4 Responses

Dear Gardener,

Thanks for contacting us. Usually when gardeners say their lilacs don't bloom, the cause is inadequate sunlight. However, in your situation a lot depends on how long the lilacs have been in the new location. If they were just moved this year, they may just be undergoing transplant shock. A photo of the foliage would be helpful. Does the foliage seem fairly healthy?

I can try to find a photo... They weren't moved. They were there when we moved to the house. I think they have been there for a VERY long time.

This is a photo of one of them taken about 3 years ago. They were in full bloom then, they bloom much less now. (excuse the prom queen - LOL)

Dear Gardener,

My apologies for misunderstanding your situation. There is a good article on the problem at: http://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-bush-not-blooming.htm It explains the various reasons a lilac may not bloom. Through the process of elimination, you may end up where you started... where the lilacs are just old. In that case. The article includes a link for rejuvenation pruning. This is done over the course of a few years. If the lilacs still refuse to put on a good show, you may have to resort to replacing them. Again, this could be done over a few years to avoid having all new (small) shrubs.