Have you ever seen a lilac bush that only blooms at the very top, or maybe not at all? Perhaps you’ve seen or have a forsythia bush that doesn’t bloom nearly as prolifically as it once did. This often happens due to a lack of or improper pruning. When done correctly, pruning can help flowering shrubs thrive and produce a bounty of blooms.

Why prune?

Pruning flowering shrubs has several benefits. Pruning will help maintain a plant’s shape, remove dead or diseased wood, and open up the canopy, allowing light and air to reach the shrub’s center. For the most part, younger branches and stems will produce more flowers than older plant material. Removing old, unproductive plant material will encourage the growth of new flowering shoots.

When should I prune?

When you prune will depend on when your shrubs bloom. Spring-flowering shrubs, such as lilacs and forsythia, bloom on old wood. This means they set their flower buds the previous year. These plants are typically done blooming by the end of June and should be pruned shortly after they finish blooming in spring. Pruning them in late summer, fall, or winter will remove flower buds and reduce the number of flowers in spring.

On the other hand, summer-flowering shrubs, like most roses and panicle and smooth hydrangeas, bloom on new growth. These should be pruned in late winter or early spring while they’re still dormant. This gives them plenty of time to set new buds for the upcoming blooming season.

Pruning your shrubs

When pruning, start by removing any dead, diseased, or damaged wood. There are two primary types of cuts that are made when pruning shrubs: heading and thinning cuts.