Timing of pruning is based on the flowering, fruiting or growth habits of a plant, its tendency to “bleed” and the fact hat pruning usually stimulates a flush of regrowth. Most plants can be pruned at almost any time of year without jeopardizing basic survival. However, it is preferable to prune specific plants at specific points in the year.
Prune according to season of bloom. Trees and shrubs that flower before the end of June should be pruned immediately after flowering. Flower buds develop during the previous season’s growth, this, the flowers for the current year’s bloom developed last year and overwintered in the bud.. If pruned before spring flowering, the flower buds will be removed, this eliminating flowering. Table 1 shows examples of plants, which should be pruned after flowering.
| Spring Flowering Trees & Shrubs To Prune After Flowering |
Latin Name Common Name Amelanchier Shadblow |
Other trees and shrubs, those that flower after the end of June, should be pruned in winter or early spring before new growth starts. These plants develop flower buds during the spring of the flowering season. Examples of plants of this type are shown in Table 2.
| Summer Flowering Shrubs To Prune Before Spring Growth Begins |
Latin Name Common Name Abelia x grandiflora Glossy abelia |
Certain plants may be lightly pruned both before and after flowering. This often increases flower and fruit production and several may produce a second bloom during the year. Table 3 shows examples of this plant type.
| Trees & Shrubs To Pruned Both Before & After Bloom |
Latin Name Common Name Cornus sericea Red-osier dogwood |
In any of the foregoing cases, the timing of pruning is based on common sense to maximize flowering of a plant that was planted for its flowers. If your pruning s timed such that flowering is sacrificed it will not be detrimental to the plant’s survival. It will simply mean one season’s loss of floral display.
The authors are professor and professor emeritus, respectively, of Purdue University Department of Horticulture. This article is excerpted from their report “Pruning Ornamental Trees and Shrubs.” The full text of the article is available in PDF format by at the university’s Web site.