The How & When of Pruning Shrubs

Question: Should I prune shrubs in my yard? How and when?

Thanks for your question! It’s important to think about pruning in advance, so you aren’t disappointed with the result! Timing of pruning is important and depends on the shrub. Be sure to check the recommended pruning timing for the type of shrub you wish to prune.

Reasons for Pruning Shrubs
Pruning can be done to remove dead, diseased, or broken branches and to maintain the health, beauty, and scale of deciduous shrubs. When you are choosing a shrub, make sure that you choose one that will be an appropriate size for its placement once it matures – pick the right plant for the right place. Why prune a shrub to reduce the size of the plant, when you can avoid that problem in the first place?

Pruning Methods for Shrubs
The natural shape of the shrub will determine how it should be pruned. Shrubs can be: 1) “mounding” with a rounded crown and a wider base, generally round or oval (like an upside down bowl), 2) “cane” with multiple shoots coming out of the ground or 3) “tree-like” with a single trunk and multiple branches.

For mounding shrubs, select the longest branches you wish to prune and make any cuts within the shrub mass so that they don’t show. Mounding shrubs are among the easiest to maintain.

For cane-type shrubs, the growth comes from the center. Select the tallest canes and prune those near the ground. Secondly, thin out canes that are crowding the center or are growing in an undesirable direction.

Finally, for tree-like shrubs, remove any rubbing branches, open up the center of the shrub to let in more light, prune branches that touch the ground, and prune any “suckers” (the little shoots around the bottom of the trunk).

Best Time to Prune Shrubs
Here are a few general rules to follow when timing the pruning of shrubs. The best time for most shrubs is late winter/early spring while the plant is dormant (not actively growing) and there is less chance of disease or pest damage. In contrast, pruning in late summer/fall will risk stimulating new growth which may not have time to harden (plants adaptation to colder temperatures) before winter sets in and potentially damaging the shrub.

However, there are exceptions for some shrubs that flower. Shrubs, which typically bloom in the spring or early summer, produce flowers on what is known as old wood. They set their flower buds at the end of the previous season, and if you prune those shrubs in late winter you risk losing the flowers.

Other flowering shrubs, which bloom in late summer/early fall, produce their flower buds on what is called new wood that grows in the spring. A late winter pruning will not affect their blooming period. There are still other shrubs, which can be pruned multiple times during the summer after each set of flowers are spent and this pruning will stimulate additional flowering.

If your purpose in pruning is to reinvigorate an old, overgrown plant, then the best time to prune remains late winter/early spring. Regardless of flower buds on new or old wood, this is the best pruning time for the overall health of the plant.

The wisest approach is to consult the pruning schedule for each particular shrub to ensure you are aware of exceptions.

References

“A Guide to Successful Pruning: Shrub Pruning Calendar,” Appleton, Bonnie Lee & French, Susan C., Publication 430-462, Virginia Cooperative Extension, 2009.

“A Guide to Successful Pruning: Shrub Pruning,” Appleton, Bonnie Lee & French, Susan C., Publication 430-459, Virginia Cooperative Extension, 2009.

“Pruning Trees and Shrubs,” University of Minnesota Extension, “How-to Planting and Growing Guides,” reviewed 2020.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.