Reviews and recommendations are unbiased and products are independently selected. Postmedia may earn an affiliate commission from purchases made through links on this page.
Q. There is an old, unpruned clematis in the garden we acquired in the spring. Beginning in June, it bore large, purple blooms of what I believe is a commonly grown variety. The flowers were all up above a mass of tangled old growth. Would it be safe to prune the vine back severely, close to the ground to give it a fresh start? When should I prune?
A. Your clematis could be Jackmanii, the best-known and probably most widely grown of all clematis varieties. Like other clematis vines that begin blooming in early summer, it flowers on the current year’s growth. If the vines are left unpruned, most new growth and flowering starts near where the previous year’s growth ended, sending the vine out of control with flowering only in the vine’s upper regions.
These summer bloomers, because the flowers grow on stems produced that same spring and early summer, are easy to prune. The idea is to get rid of most of the old growth to make way for the new. To get lots of new growth, and flowers low down on the vine, prune the plants back hard in late winter, cutting above the first or second lowest set of plump buds on each stem. On older plants, cut immediately above strong sets of buds 30 to 60 cm above the ground. As new stems grow, thin them out as needed to avoid overcrowding.
Not all clematis vines are pruned in the same way. Spring-flowering clematis, such as Clematis montana (anemone clematis), C. alpina (alpine virgin’s bower) and C. macropetala (downy clematis) bloom on growth produced in the previous year. They require little pruning except to restrict their size, reduce tangling and remove dead wood. They are pruned after flowering has finished.
When these early bloomers become a tangle and you want to renew them, cut the stems back to good buds close to the ground in June. The new growth made in summer will yield the next spring’s flowers.
Recommended from Editorial
It’s not too late to plant garlic
Timing is key: Planting garlic amid changing weather patterns