Wisteria – Control
Its flowers are gorgeous but the nature of a wisteria vine is to conquer everything around it. Cascades of lavender or white blooms announce that the vine has woken up after a winter nap and is poised to start climbing once again.
Many people have trained Chinese wisteria, Wisteria chinensis, over an arbor, only to see it attempt to climb the side of their house. Other gardeners prune the vine each year to make a specimen tree-form wisteria… but if pruning is neglected the vine will snake across the landscape looking for the nearest vertical surface to climb.
Like most plants, wisteria can be controlled by spraying the leaves with glyphosate (click for sources) or triclopyr (click for sources). Care must be taken with either chemical not to spray nearby ornamentals.
If the wisteria has climbed too far into a tree to reach the leaves with spray, simply sever the main stem at ground level. Then paint glyphosate (click for sources) or triclopyr (click for sources) onto the lower cut surface immediately after cutting.
The chemical will be sucked back into the root system for a small distance but I’m positive it won’t kill the entire root mass.
You’ll have to remove soil sprouts by spraying, clipping, or mowing as soon as you spot them for at least three years, thereby eventually starving the roots and killing them.
If you like wisteria blossoms but fear its invasiveness, try American wisteria, Wisteria frutescens. It blooms a bit later than Chinese wisteria but is just attractive.