Pruning a wisteria isn’t complicated. It’s simply a matter of applying a bit of tact rather than taking a chainsaw to it. If the wisteria grows reasonably well, pampering it a little will reward you with its stunning flowers!
Wisteria pruning, an essential task that can grow tall
In the Tree and Shrub Pruning category, this isn’t the most difficult task, though it’s iconic. Wisteria, which can still reach about 10 to 15 m (roughly 33 to 49 ft), remains a garden staple, a flowering fixture straight from Asia, and more specifically Japan.
Its flowering is simply spectacular, and its hanging flower clusters aren’t without reminding one a little of acacia, even though wisteria flowers aren’t edible.
Hardy is a term that can safely be applied to wisteria, which resists drought (not for too long, though) and can withstand very low temperatures down to -20°C.
It will, however, appreciate sandy soils without too much lime and will prefer sunny locations.
Once the bloom season has passed, pods that closely resemble broad beans of about 15 cm long appear, but they are no more edible than the leaves or the flowers… What a pity!
Why prune wisteria?
The primary reason for pruning wisteria lies in its potentially very rapid growth, which you need to control, especially if it threatens to overtake a roof.
Pruning wisteria, especially in its early years, will both train it in space and encourage it to flower and help prevent it from taking over.
When to prune wisteria?
The sap of wisteria descends relatively slowly at the end of the season, so it is wiser to prune it at the very end of winter, just before what is called the “start of vegetation”.
Early March will thus be the ideal time to give your wisteria a good kick and spur new shoots and plenty of flowers.
How to prune wisteria?
Pruning a wisteria isn’t a complicated task, and this is all the more true since it is particularly hardy and a misstep with the pruners won’t have serious consequences.
Begin by removing dead wood and the branches that are growing poorly (you need an eye for it, but you’ve watched it all year…). Then continue by removing branches that are in excess, i.e., branches that are too numerous growing side by side.
Once your wisteria is thinned out, you can finally tackle the pruning proper by reducing last year’s growth by about half… You don’t skimp on wisteria pruning!
