Our spring-blooming shrubs have been glorious this year—flowering quince (Chaenomeles speciosa), Forsythia, Fothergilla, some hydrangeas (Hydrangea spp.), mountain laurel (Kalmia latifolia), mock orange (Philadelphus x virginalis), azaleas and rhododendrons (Rhododendron spp.), lilacs (Syringa vulgaris), many Viburnum species, and Weigela are in this category. As their blooms start to fade, plan now to prune these shrubs for next year’s bloom!
Pruning time matters
Look at your shrubs while the blooms are fading to decide where you need to prune. If your shrubs didn’t look glorious this year—or you had no blooms at all—pruning might be the culprit! Timing is critical, especially for pruning spring-blooming shrubs that develop their flower buds during the summer and fall of the previous year. This is often called “blooming on old wood.”
By mid-June, spring-blooming flowers will likely be gone, and your deadline is approaching to prune. Plan to finish pruning these shrubs soon after flowering—no later than the 4th of July. Pruning in late summer, fall, winter, or early spring will remove the buds getting ready for next year’s show!
How to prune
The North Carolina State University Extension has recently updated their series of publications on pruning (see links, below). “Before the Cut” introduces you to information on how to prune to open up the top of the plant to permit light and air to reach the interior, to promote new plant growth, maintain plant size, encourage flowering, remove diseased or dead limbs, and help control insect and disease problems.
When thinking about pruning, consider the “one-third” rules: remove about one-third of the oldest wood at the ground level and cut back one-third of the younger, newer canes about one-third of their height per season.
The section of “Before the Cut” on “Plants that Flower on Year-Old Growth” is most relevant to pruning spring-flowering shrubs. The publication on “Pruning Specific Plants” provides more details on each individual shrub species.
North Carolina State Extension: “General Pruning Techniques,” which provides information on timing of pruning, pruning methods, maintaining shrubs, and specialty pruning.
Pruning methods discussed include size reduction:
• Heading back, the removal of one-year-old shoots recommended for plants that have outgrown their allotted space, and
• Reduction cuts used to train trees and shrubs and to control the direction of growth, among other purposes.
There is extensive information on cutting both small and large branches—with details about the proper placement of cuts, the guidance to “not leave a stub” following pruning, and the admonition to “never apply wound paint or tar” to the cut.
The section on maintaining shrubs provides guidance on the management of growth in deciduous, broadleaved evergreens, and needled evergreens, including the appropriate time of year to prune each in order to achieve maximum benefit in your landscape is provided.
The section on specialty pruning describes a number of techniques not commonly seen in most home landscapes. These include espalier, pleaching, pollarding, and topiary.
Article written by Extension Master Gardener Volunteers.
For more information:
Before the cut:https://content.ces.ncsu.edu/before-the-cut
How to prune specific plants: https://content.ces.ncsu.edu/how-to-prune-specific-plants
General Pruning Techniques: https://content.ces.ncsu.edu/general-pruning-techniques