My experience of pruning Wisteria
I have been lucky enough to have two wisteria vines in my gardens. I treasure them as majestic, beautiful plants which are simply stunning in flower yet still graceful and well worthy of space when only in leaf.
My first wisteria I planted myself having seen one in full flower and fallen in love. I placed it at the base of a sunny back wall in between two windows, the plan being that it would grow up the middle and then across each side.
I am not a patient person by nature but in this case, I had to find some. My instinct was to just let it go so that it covered its allotted space as soon as possible and produced the abundant display of flowers I craved. This would not have worked! First, I had to establish the basic framework of the plant which takes a few years.
My second wisteria I inherited as an established plant on a pergola. It had all but stopped flowering, so my task was to rectify this.
The solution to both issues was pruning. An unpruned wisteria will soon end up a huge, unruly tangle of often unflowering stems that find their way behind gutters, into the roof, covering a window or swamping other climbers. Pruning doesn’t only control the plant and provide structure; it also promotes flowering.
Wisteria is pruned twice each year in late Winter/early Spring and then again, a couple of months after flowering. It flowers on short, lateral spurs of previous year’s ripened growth and the object of the pruning exercise is to promote these spurs and control new growth once the plant is established and has covered its allotted space.
In July/August tie in the new leafy growth that you want to keep in order to extend coverage. Cut back all the rest to between 6” and one foot of a main branch and remove any new shoots coming from the base of the plant. In January/February cut the laterals you shortened in the summer back even further to leave just a few buds.
And that’s it! In my experience the tricky bit is reaching the relevant bits of plant rather than the actual pruning.