A guide to trimming back lilac and keeping it blooming

Knowing how to trimlilac busheskeeps them vibrant and neat.

Here’s what it’s crucial that you know about how to prune a lilac bush.

Lilacs set next season’s flower buds almost immediately.

Lilac bush with light pink flower clusters on spike next to large leaves

The Spruce / Steven Merkel

Late pruning in the summer or fall will sacrifice blooms for the next year.

The Spruce

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how to prune a lilac bush illustration

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Prune just beyond buds that face away from the center of the plant.

This technique will cause more branching and create a denser shrub.

Fortunately, rejuvenation pruning revives an old lilac in about three years.

Materials and tools to prune lilac bushes on wooden surface

The Spruce / Steven Merkel

There are two approaches you could take.

Then you’re free to start regular maintenance trimming.

Fertilize the plant with compost or a balanced fertilizer to prompt new growth.

Red loppers pruning dead stem closeup

The Spruce / Steven Merkel

New shoots will develop throughout the growing season and into the summer.

The following spring, prune out the spindly growth and maintain the healthiest shoots while shaping the plant.

Encourage branching by cutting back the remaining shoots to just above a bud.

Thicker stems from lilac bush being cut off with pruning saw

The Spruce / Steven Merkel

Carry on with regular maintenance pruning after this.

It has a vase-shaped crown with spreading branches and produces showy white flowers in June.

They rarely require maintenance pruning, though it’s possible for you to trim when necessary for shape.

Lilac bush stems with buds and new growth being pruned with red loppers

The Spruce / Steven Merkel

New lilac plants should begin blooming within two to five years.

Deadheading the spent flowers encourages new bud development for the next spring.

Once the plant has matured, you don’t need to take the time to deadhead.

So don’t panic if your lilac isn’t as vibrant from year to year.

you could cut your lilac bush back 6 and 8 inches above the ground for a drastic rejuvenation pruning.

Fertilize the plant with compost or a balanced fertilizer to encourage new growth.

Pruning Large, Overgrown Shrubs.Iowa State University Extension.

Growing Lilacs in Montana.Montana State University Extension.

Pruning Lilac Bushes: Expert Response.

U.S. Department of Agriculture: National Institute of Food and Agriculture.