This summer I painted my house and replaced the gutters. This required 20’ of a 16 year old wisteria to be cut back to the 1” or bigger branches. I had grown the plant on a cable attached to the eaves. The original trunk is about 6”. Is there anything I can do to help it sprout new branches?
Benton County Oregon
Ask an Expert can give you some tips for renovating your wisteria.
As you have described it, your wisteria will probably have no problems sprouting new branches. Their general reaction to hard pruning is to come back aggressively. However, creating your new display will take several years.
It seems you have done well over the past 16 years in maintaining the wisteria, so the art of pruning is familiar to you. As the new vines develop from the original trunk, direct their growth onto your supports (cable or trellis).
At the summer pruning, take out branches that cause congestion and allow others to develop its new structure. The winter pruning serves to clean up and further establish that framework. For the first few years, growth will likely be all green (no flowers). But your work is to restore a strong support for continued growth and health of the plant.
Once the new structure is established, continue traditional wisteria pruning. Steve Renquist, OSU Horticulturalist in Douglas County, wraps it up succinctly:
- Summer-July or August cut back shoots to 10-12”, this helps get sunlight to wood.
- Winter-February cut back shoots to three to five buds.
The Royal Horticultural Society has a tip for wisteria growers after a hard pruning, such as yours: “Hard pruning will stimulate strong, new growth so it is better to avoid feeding in the first spring after hard pruning.”
Enjoy your wisteria,
Thank you so much! All good ideas I had not come across before. Rosemary