Can my neglected heathers be saved by pruning, and when is the best time of year to do it?
Sheila Bietighofer, New Rochelle, NY
Photo/Illustration: Jennifer Blume
Karla Lortz, owner of Heaths & Heathers, a nursery in Shelton, Washington, replies: Heather (Calluna vulgaris) must be pruned annually because, as the fading flowers fall, bare spots develop in the middle of the plant as the stems get too long and hang down towards the ground. In short, these plants—which are hardy in Zones 4 to 7 (–30°F to 0°F)—will become ugly and unruly without annual pruning.
To regenerate an old, neglected heather, severe pruning may be the only way to save the plant. Prune the plant back close to its base, being careful to limit your cuts to branches that are green while avoiding woody stems. Also, check to see if the drooping, outer stems have rooted themselves. Cut and replant the rooted stems and discard the main plant if it’s unsalvageable. It’s worth a try, as the other option is to replace the entire plant.
To keep both new and rejuvenated heathers tidy, an annual pruning regimen is best. Cut the flower stems off at their base once the plants finish flowering each year before new growth buds form in late fall or early winter. After pruning, new shoots will emerge from each branch that is cut, resulting in fuller, bushier plants. Be aware that late-fall and early-winter pruning can leave the freshly-cut branches vulnerable to stem-splitting from winter ice damage in colder climates. Waiting until early spring in Zones 4 and 5 (–30°F to –20°F) to prune will save time and energy, as any winter damage can be cut away at that time as well.