For years our wisteria has brought us such joy. We even have our Christmas lights strung through the branches. We enjoyed the fabulous fragrance and huge hanging blossoms. This year there was nothing. Not one sign of growth. I kept pruning the sucker shoots however. Just recently I discovered small holes in lots of the branches and powder on the ground. I'm positive termites have had a field day. With sadness we need to have our wisteria cut down. I know the shoots will continue to grow so how do I kill the stump and the sucker shoots. -
Termites in Our Wisteria and How to Kill the Stump
Certified GKH Gardening Expert
It is probably not termites, but rather borers, specifically roundheaded borers. They can get into wisteria and cause damage like you describe. This article has more information:
But, if you still want to kill the wisteria, cut it back and paint the fresh cuts with undiluted Round-Up. The plant will "suck" this back into the root system and that will work to kill the roots. Repeat this with any suckers that appear in the next few months.