By Joantorode
United Kingdom 
urgent help needed please!I planted wisteria 20 yrs ago and it is very strong and abundant flowering twice a year; alas I need to cut it back now in order to have the external windows of the house and shutters painted. I dont want to be over drastic and risk any kind of die-back. Can you advise which part of the branches is the best to prune.
25 Jul, 2017
Previous question
late July or August is when Wisteria is due for its summer prune anyway. There's a video in the link below that shows you how, but if you need to take off more to get to the windows, it won't kill the plant, though it it might reduce flowering a little next year. You'll have to copy and paste the link I'm afraid, this site's not up to date on the technical front
https://www.rhs.org.uk/videos/advice/pruning-wisteria
25 Jul, 2017