Q.Wisteria is Dead – Why?
I planted two wisteria on the southeast facing front of my house about ten years ago. They have done pretty well, with one being more vigourous than the other, which could be explained by the ground conditions. Both have flowered consistently well for the last 4-5 years. The less vigourous has flowered as well as it ever has this year, but the more vigourous one, having formed buds during the winter, has not flowered or leafed out. I can find no part of the plant which is green under the bark. There are no signs of disease, which I have looked up. Can you please suggest any reason why this may have happened?

Certified GKH Gardening Expert
I would check for crown or root galls. It sounds like something is choking the plant and galls would do that. Here is some information on them that may be helpful: https://www.gardeningknowhow.com/plant-problems/disease/how-to-fix-crown-gall.htm