Time to Prune Wisteria
There are relatively few plants you absolutely have to prune. Wisteria is one of them. If you ignore this rampant vine, it will eventually strangle your trees, bushes, house, and passing clouds. But how do you prune it and when? Will a pruned plant still bloom in spring? As always, Grumpy has the answers.
Wisteria is kind of weird for a woody vine, because it blooms on both old and new growth. Flowers appear in abundance in spring and then sporadically throughout the summertime. That's why it seems counterintuitive to say prune it now. Won't that remove most of the flower buds it made last year and ruin the spring bloom? Not if you follow Grumpy's advice.
Depending on the size and height of the vine, you'll need sharp hand pruners and maybe loppers and a ladder. Now look at that Medusa-like tangle of branches, twigs, and runners you call wisteria. You're going to give a very precise haircut.
WATCH: Why We Love Wisteria
Long side branches called canes grow from the wisteria's main trunk. Most people attach these canes to some sort of structure, such as an arbor or pergola, as they would for a climbing rose. Slender, twiggy shoots then grow from the main canes. It's these shoots you need to trim now.
Shorten each shoot to 6 to 8 buds. These buds will still bear flowers. Keep pruning like this every February and short, spur-like branches will develop loaded with flower buds.
When about later on in the summer? Any pruning needed then? Yep, but not as much. Pinch out the tips of any long, twining runners searching for something to climb. This stops them in their tracks. If the vine grows too vigorously, feel free to give it another haircut, though not as short as the winter one. Don't be surprised to see a few flowers open afterward. Watch out for suckers growing near the base of the trunk. They like to slither along the ground like snakes until they find something to grab. Cut them off at the trunk.