Heirloom Expert: Lilacs Not Blooming Up to Par?

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Photo by Fotolia/Denis Tabler

My lilacs aren’t blooming the way they used to. It seems every other year is decent—on the off years, there’re only a few flowers. My wife loves the fragrance … Can you help me get the blossoms I remember?

I think of lilacs as a one-trick pony, but with an incredible trick. The beautiful flowers with unmatched fragrance are what spring is all about. It’s my wife’s favorite flower too, so they better bloom in profusion, right?

It’s very common for lilacs to get tired or shift into sporadic blooming. There are a few things to consider when trying to diagnose the problem. Lilacs set their buds right after blooming; if they’re pruned when the buds are there, you’re removing the flowers. I like to give the plan a haircut as soon as the blooms fade. This forces the plant to put on more buds for next year’s flowering.

The other thing which helps is to remove a third of the biggest and oldest stems. It’s going to be a leap of faith cutting those large trunks, but it’s for the good of the plant.

One more note on flowering shrubs. Most of the country struggled with a tough winter which can affect the blooms of hydrangeas. Don’t prune out dead wood until you’re well into the start of summer and you can easily identify the shoots that don’t flower.

– Doug Oster, contributing editor

Doug is the Pittsburgh Post-Gazette’s Backyard Gardener and co-host of The Organic Gardeners radio program on KDKA.

Mother Earth Gardener
Mother Earth Gardener
Expert advice on all aspects of growing.