Is it too late to prune wisteria? We are putting our house up for sale in May and the wisteria is out of control right now. I realize looking at a previous question i should have pruned late winter. But is it too late now? What will happen if I do prune it now?
Thank-you for contacting Toronto Master Gardeners with your question.
You should go ahead and prune your wisteria now for a couple of reasons. As you noted, the advice you will see on our website and online recommends 2 pruning sessions per year for wisteria; late winter and mid-summer. Pruning in spring rather than late winter runs the risk of removing flower buds, resulting in reduced flowering. Wisteria is a very strong grower, however (some would call it aggressive). Pruning a little later than the optimum time certainly will not kill the plant. In your situation it is better to have your vine tidied up even at the risk of some blooms. The other point to consider is that “late winter” may occur at different times in different locations. The pruning advice from the RHS in England suggests January/February, but keep in mind that their bulbs are already up by that time. Our winter is dragging on with the first real signs of any growth just occurring in the last couple of weeks! The idea is to prune before the vine begins to grow.
The articles at the links below explain the techniques to use for wisteria pruning. Basically, you need to remove the long growths back to 3 buds past the trunk or scaffold branch. This will result in increased light for flowering, less energy spent on leaf growth and the generation of new flowering spurs.
https://www.rhs.org.uk/plants/wisteria/pruning-guide
Best of luck with your pruning project!