How far back can I cut Wisteria without killing it?

If it's more than 3 years old, you can probably cut it back to the ground without hurting it. If it is younger, you can still cut it back by at least half, assuming you are growing it as a vining form. (Some people train them into a little tree-like shape, and if that's the case, trim what you need to in order to maintain the shape.)

How far back can I cut Wisteria without killing it?
I've got one that I'm trying to kill. I've cut it to the ground and it keeps coming back up. I think you will find that you can cut it down completely and it will do the same. If it has a good root system it will survive. I have also cut one down because it wouldn't climb. It just sat there and wouldn't grow. I cut it down and when it came back it came back as runners and I haven't had any more trouble. Good luck!!
Reply:Well without knowing the measurements of your Wisteria, I would say cut no more then 1/3 of the plant.
Reply:You can cut it all the way back to the ground. Remember though that it blooms on last year's growth. Unless you cut it back immediately after it's done flowering, you'll be removing next years flower buds.
Reply:I have come to believe that you cannot kill wisteria.