There’s an ideal time for trimming flowers
QThere are several springflowering shrubs in my newly acquired garden. Some seem rather overgrown and crowded. When and how should they be pruned?
A: The post-flowering period is an ideal time for trimming, thinning and shaping spring-flowering shrubs for visual appeal, the health of the plants, and promotion of fresh, flower-bearing growth for next spring.
For shrubs that have a grouping of stems emerging directly from the ground, such as red flowering currant, once the shrub is well established, keep it youthful by cutting one or two of the oldest stems to the ground. To shape, trim remaining branches back to outward-facing buds.
Forsythia usually needs some thinning to relieve congestion. Select some of the oldest growth to cut back, making the cuts right above strong new shoots that are pointing outward. The oldest growth will be the thickest around.
Rhododendrons that have grown lanky and sparse of foliage can be renewed. Cut away the lankiest, most barren branch close to the ground. Next spring, as long as the cut area is regrowing, cut down another one or two branches. Eventually, you’ll have a new plant. Thin newly formed stems as they develop, leaving only the sturdiest.
Camellias are best shaped and cut back during or just after flowering. Make cuts right above outward facing leaves.
A light annual post-bloom shearing helps to keep winter heathers comely. Avoid cutting into old wood.
Prune lilacs as soon as the flowers fade. Remove the spent flower spikes by cutting right above the first pair of leaves beneath them. An old, overgrown lilac can be renewed by cutting out a third of the old wood each spring for three years, after which you’ll have a new, more compact flowering shrub. It’s a wise practice anyway on established lilacs to cut down a few of the oldest stems each year.