Hello,
I have cut back my 2 clematis early in spring. Last fall I mistakenly did too early (end of summer) to the RIGHT one.
The other one (LEFT) was not done anything on purpose to see how it grows.
As of today the Left one is growing larger. Which has been actually opposite. (It had been more compact than RIGHT one)
My questions:
1) Does clematis need a cutback?
2) If YES, when is the best timing?
Posting from Ottawa, ON
When and how much you prune clematis depends on the variety. Without knowing which those two plants are, we can’t tell you what to do with them, specifically. However, the following information from one of our earlier posts describes the proper way to prune clematis:
1) Early flowering clematis
Early flowering clematis typically bloom in April and May, from buds produced during the last growing season. Prune these plants immediately after blooming, but no later than the end of July in order to give the plant enough time to produce new buds for next year. Start by removing shoots that have bloomed. If necessary remove dead or damaged stems. If growth is congested then cut out older stems to the base and thin the rest. Avoid cutting far into the main woody trunks. Cutting off too much may affect next years flowering. This group includes C. alpina, C. macropetala, C. armandii, C. montana, and C. chrysocoma.
2) Large-flowered/mid-season clematis
Large flowered hybrids like ‘Nelly Moser,’ ‘Miss Bateman,’ Lasurstern,’ and ‘Duchess of Edinburgh’ bloom in mid-June on stems from the previous season and often will bloom again in late summer on new growth, though these blooms tend to be smaller. Remove dead or weak stems in late winter or early spring, leaving the best of last year’s buds. Once they finish blooming, deadhead all bloom stems or cut the plant back to 12-18” to force new growth for a second round of flowers.
3) Late flowering clematis
This group’s flowers are produced on the current season’s growth and are the easiest to prune. Some types begin blooming as early as June and continue into the fall. This group contains the greatest number of clematis. In late winter or early spring, cut the plant back to 24-36” since no old wood needs to be maintained. Varieties like C. ‘Jackmanii’, C. viticella, C. flammula, ‘Royal Velours,’ and ‘Duchess of Albany’ fall into this category.
Hopefully, you remember which varieties you have. Or you can look at one of the many clematis sites to see if you recognize your plants. For example, here’s a good list from the Royal Horticultural Society.