Blackwelder: Controlling wisteria

Published 12:00 am Sunday, April 5, 2020

Wisteria is used in many landscapes and readily found in local garden centers and nurseries. The plant was introduced to the United States from Japan and China in the 1800s as an ornamental vine. Most gardeners keep the vine in check with constant pruning on a well-constructed trellis. However, some ardent gardeners often prune and train the vine into a small tree.

Wisteria has problem with its out-of-control growth habit. The vine has the ability to climb up almost anything, including trees, plants, buildings, etc. searching for light. The vine’s excessive growth produces dense shade limiting plant growth and development. The vine’s growth is only limited by growth of plant or structure, often reaching lengths in excess of 50 feet with a diameter that has been measured at 15 inches.

Many homeowners with wisteria-permeating trees and open areas need to consider controlling the vines. Large wisteria vines should be cut leaving a stump as close to the ground as possible. Apply a herbicide solution to the stump immediately after cutting the vine. Brush killers with active ingredient of glyphosate (Roundup) and/or triclopyr applied to the fresh stump translocates to the roots. Foliar applications may also be necessary for smaller foliage plants. The best time to apply an herbicide is in the spring and summer when wisteria is actively growing.

Darrell Blackwelder is the retired horticulture agent and director with the North Carolina Cooperative Extension Service in Rowan County.