I trim both my Wisteria bushes( a pink and a lavender) multiple times during the summer and on into Autumn just to keep it under control. I also shovel prune them maybe every 3 years or so. I usually stop pruning in late September, early October. I started training mine on an arbor this Spring. Didn't take long for both bushes to cover it. I live in Maine and the bushes are over 15 years old. NancyLouise

The short answer is 'No' :-) The more you prune a wisteria, the more likely it is to produce a heavy flower crop. Plant Amnesty is a local pruning resource (probably the most misunderstood gardening practice there is) and they have produced one of the best wisteria pruning and training guides I have encountered. How to prune wisteria.

Hopefully your wisteria is a grafted plant - seed grown wisteria can take years (as much as 15-20!!) before they will bloom.

I don't know where you are or what your zone is, but I stopped pruning mine in mid-September in order to have any blooms in the spring. I'm in north central CT, zone 6b. I followed White Flower Farm's advice, though they are a bit colder than my zone.

Thank you for all your responses and the great information.

You need to prune the roots of a wisteria for it to flower properly. Take a very sharp flat spade and sink it into the soil about 4 feet from the main trunk. Do it now in the Fall. You want to sever as many roots as you can at that radius. That will stimulate flowering in the Spring. What you are doing is preventing the plant from taking up nitrogen. This will encourage less vegetative growth and more reproductive growth (flowering).

http://web.extension.illinois.edu/dmp/palette/100425.html

Steve