Wisteria: Summer Pruning

If you have ever seen a well trained Wisteria in full bloom in June, you may be tempted to add one to your garden. Keep in mind, Wisteria isn’t one of those plants you can put in the ground and forget about. Pruning in winter is very important, but there is pruning needed in summer, as well.

Before you get started, keep in mind your objectives:

  • To cover the support structure with well placed branches
  • To promote heavy flowering close to the main framework of branches.

Specific Summer Pruning Objectives:

  • To keep the vine in bounds
  • To increase sun penetration
  • To tie in new shoots to cover the support

SAFETY FIRST:

Working large vines that reach several stories overhead can be very dangerous. Follow these rules when pruning on a ladder:

  • Asses the support structure. Even pressure-treated wood and cedar will rot over time. Make sure the structure can support the vine and any weight you might put on it while pruning.
  • Nantucket is windy! Avoid working on a ladder on windy days.
  • Work with a partner. Someone on the ground to clean up and steady the ladder is very helpful.
  • Never stand on the top two rungs of a ladder
  • Work from below a pergola. Never climb up on top to prune. It is very easy to trip in the tangled vines or damage the laths.

With the objectives in mind, and safety as the top priority, begin to prune.

  1. Cut back long tendrils to 6 inches. These vegetative shots will not flower and will shade the inner portions of the vine next to the support. In order to ensure good flower bud set, sun must penetrate into the Wisteria during the growing season.
  2. Remove long side shoots at the base of the vine. This lateral growth will run along the ground and root, causing the wisteria to spread. *If the shoots arise from below the swelling where the Wisteria was grafted, it is even more important to remove them. It is nearly certain that these shoots will not possess the characteristics of the scion (the desirable grafted portion of the plant) and may be even more aggressive and difficult to control.
  3. Tie strong shoots onto empty portions of the support. It is best to work systematically across the wisteria, pruning and tieing as you go. It helps to keep a center-pull ball of just twine in your pocket; this way, there is no need to climb up and down the ladder each time a vine needs to be tied.

Wisteria 'Prolifica'

Need a better visual? Check out our YOUTUBE video : www.youtube.com/watch?v=9BxUKPA4vx0&feature=youtu.be