Do your flowering shrubs need a makeover? Perhaps it’s the overgrown shrub that craves your contact whenever you use the front door or carport. Maybe it’s an old shrub that lost its vitality and produces few if any flowers in its dense thicket of crisscrossing branches. Then there’s the shrub that becomes top-heavy or “leggy”, with most of its leaves clustered at the top, revealing bare or leafless stems below. If you want to improve access to your home or your view from windows now hidden by leaves and branches, consider these three options.
This drastic approach requires that you cut down the shrub to within 6 to 12 inches of the ground before spring growth begins. Most broadleaf shrubs respond well to this treatment, such as azalea, glossy abelia, holly, and Japanese cleyera. When growth resumes in the Spring, expect to see medusa-like sprouts emerging from the pruning cuts and from dormant buds on the stems. Keep 2 or 3 of these soft green shoots, selecting upward- and outward-growing stems, and remove the rest. As these shoots mature, they will eventually become the permanent structure of flower-bearing branches.
Renewal or rejuvenative pruning draws little attention from your neighbors. Instead of removing the top growth at one time, prune out only a few shoots at a time over a period of three years. They will be replaced by more vigorous younger shoots that will flower next year. The best candidates for renewal pruning are multi-stemmed shrubs that include forsythia, hydrangea, spirea, summersweet, and sweetshrub.
In the first year of renewal pruning, remove one-third of the oldest, thickest stems. Prune them close to the base or crown of the shrub. The next year prune away one-half of the remaining old stems and remove a portion of long, lanky shoots to encourage branching. In the third year, remove the remaining old stems and cut back wayward-growing branches that extend beyond the crown of the shrub. Cut the branch to a vigorous side shoot or outward growing bud.
You could wait until after the shrub flowers in the Spring or prune them now, knowing that you will sacrifice some of the flowers. I prefer to rejuvenate the shrub when it’s dormant without any interference from the leaves.
Regardless of which pruning technique you choose, remove dead, damaged, and diseased branches at any time of year. For additional information on pruning shrubs, see HGIC 1053, Pruning Shrubs, and The art and science of pruning.
Like Cinderella’s stepsisters, admit that the shoe doesn’t fit, and your shrub is simply too large for its space. With the wide selection of compact and colorful species and cultivars, you’re bound to find the right shrub that fits your landscape without requiring a monthly pruning intervention.