Prune Spring Flowering Shrubs after Blooming
By Kim Toscano
When it comes to pruning, timing is everything.
In gardening there is an exception to every rule. While most of our trees and shrubs are pruned in late winter when plants are still dormant, there is a select group of plants for which pruning should be postponed. For the best floral display, wait to prune spring-blooming shrubs like forsythia and quince until after plants finish flowering. You will be rewarded with better flowering from one season to the next.
Why Wait to Prune Spring-Blooming Shrubs?
The key to knowing when to prune a plant is understanding flower bud development. Different types of plant produce flower buds at different times of the year. Some produce flowers on the rapidly expanding spring growth. Others form flower buds during the summer months, on plant tissue that will overwinter and bloom the following spring. This later group includes plants that flower in winter and spring. If you were to prune these plants during the winter, you would remove all those flower buds waiting to open when spring returns.
When to Prune Spring-Blooming Shrubs?
If we don’t prune spring-flowering shrubs in winter with the rest of our woody plants, when should they be pruned? The answer is simple: after they finish flowering. This will be slightly different for each species, as bloom times vary considerably. For each different spring-bloomer, simply wait for the last flowers to fade and then grab those pruners. Winter-blooming shrubs can also be pruned after they complete flowering.
Remember what I said about exceptions? Here’s one – severe pruning, such as rejuvenation or renewal pruning, should take place during the winter months. You will sacrifice flowers, but only for a season. Another exception: remove diseased or damaged stems as soon as you notice them, regardless of the season.
Which Plants Should be Pruned after Flowering?
Several evergreen shrubs bloom during the late winter and early spring months, including camellias, loropetalums, mountain laurel, and azaleas. Prune these plants immediately after they finish flowering. The same is true for spring-blooming deciduous shrubs such as lilac, mock orange, forsythia, and flowering quince. Viburnums also fall into this category, however, if you wish for plants to produce berries you will want to limit pruning to only those branches impacting the health or form of the plant.
What to Cut?
As mentioned above, dead, diseased, or damaged material—the 3 D’s of pruning—should be removed immediately. After blooming, selective pruning is done to promote plant health, improve flowering, and maintain a pleasing form. Remove weak, spindly stems by cutting back to the base. Also look for stems that cross through the center of the plant. Cut these back to their point of origin. Removing crossing branches will improve plant form and allow more light to reach inner branches, which promotes blooms. Next, trim any overly long, unruly shoots that detract from the plant’s appearance by cutting back to a lateral branch or just above a bud (called a thinning cut). Thinning cuts are preferred to simply clipping the tips of branches, as they promote more natural growth.
Understanding the right time to prune flowering shrubs can mean the difference between an abundance of blooms and a garden stripped of its flowers. For the best display season after season, prune spring-blooming shrubs after flowering.