Die back of new growth on a tree wisteria.

My tree wisteria has been in the ground for 3 years. Every year the tips of the new growing die off. I would appreciate any insight as to what is causing the problem and how to treat it.

Is it in the spring that you're noticing this, or in the summer? If it's in the spring, then it's probably cold weather, you're near the lower end of their hardiness range and tender new growth is very easily damaged if you get a late frost. Unfortunately there's not much you can do unless the plant is small enough that you can throw some frost cloth over it when you're expecting a cold night. But it shouldn't matter, wisteria is a pretty aggressive grower and I imagine it'll put out plenty more new growth later on in the season.

My wisteria tree has been in the ground 3-4 yrs also. I've had the same problem for two yrs in a row. We had late spring freezes and that is what caused my problem. The blooms were frozen back this year :-(
It has all new growth now and looks great. They are very hard to kill (at least here in my zone)