CLEARING UP CLEMATIS CONFUSION
During the nearly 30 years that I have hosted the open-line radio show “Garden Talk” one question has been asked far more frequently than any other, “How do I prune my clematis?”
There seems to be more confusion and trepidation about pruning this vine, with its enthusiastic growth and amazing display of blooms, than exists for any other plant. It also seems that no one can ever remember what variety of clematis they’ve planted. It’s as if a few short months after planting, the name vanishes into thin air, never to be recalled again.
Not to worry, here is the answer to the question “How to prune clematis, especially if you don’t remember the variety name.” The question to ask is “When does this clematis bloom?” If it blooms early in the growing season (before the end of June) it’s flowering on old wood, produced the previous year. A hard pruning in spring, where you are removing all of the growth save for a foot or two at the bottom, would result in no flowers at all this year because you’ve cut off all the growth that contains potential blooms.
Pruning on these types should consist of nothing more than cutting out dead wood after the vine has budded out and removing weak stems after the bloom is finished.
If your clematis blooms in early summer and beyond, it’s blooming on current season’s growth. Now is the time to look at the vine for strong sets of buds forming on the lower growth near the ground, and to cut back all of the top growth (yes, all of it) to those buds. If you don’t do this eventually all of the new growth and flowers will be at the top of the vine, not up and down its entire height. Cutting back hard shouldn’t be a problem, as clematis look rather disheveled after the winter anyway.
The pruning question would be an easy one to answer if there were only two types, but there’s a third group to complicate matters. These bloom early on old wood, and later on new wood! Pruning these types consists of again removing any dead wood or weak stems and then cutting stems at differing heights to produce a balanced plant while creating space for new growth and later blooms.
Sometimes it’s not a bad move to cut back a plant that hasn’t been doing well regardless of what wood it’s blooming on. Start with a clean slate, allow the plant to regenerate from its root system and give up a year of bloom for long term benefits.
So there it is in a nutshell. Clematis are quite forgiving creatures; incorrect pruning won’t kill them, a lack of pruning will not cause them to quit blooming. If you want them to perform at their best, however, the right pruning at the right time will make all the difference when it comes to enjoying the spectacular blooms of this most popular of vines.