Wisteria is a firm favourite amongst many people. Its purple pea like flowers and incredible fragrance is unmistakably distinctive. Wisteria has a reputation of being complicated to prune, but it really isn’t.
Wisteria is pruned twice a year, in the late summer (July or August) and in the winter (January or February.)
Why Prune Twice
Wisterias can be left to ramble unchecked if space allows but they will flower more freely if pruned twice yearly, when you know how, it’s simple. The removal of the growth in the summer allows more air and more sunlight to get around the plant. This leads to the wood ripening and increases the chances of flower bud formation. You have considered the long whippy growth to be a good sign, and it is! But these will need taking back shorter in the summer to encourage short flowering spurs. In the late summer the whippy growth needs pruning to 5 or 6 leaves after flowering to control the size, pruning in early or midsummer will disrupt the formation of flowers for the following year.
Then in the winter, prune the same growth you pruned in the summer to 2 or 3 buds, when the plant is dormant and leafless. This just tidies it up where you can now see the framework and prevents the leaves obscuring the flowers when they form.
Where Wisteria Can Be Trained
Wisteria can be used in any size garden where it will be kept under control. If you have a small garden, wisteria can be trained up a wall using horizontal support wires. Over time, with pruning twice a year these will build up a good strong flowering spur system.
With their long flowers, wisteria is best admired where they can hang free. Over a pergola or an archway allows the flower to dangle through the structure, allowing the fragrance to circulate the air under the pergola while you’re sitting there.
For Maximum Effect with Wisteria
Wisteria floribunda has the longest flowers racemes and is best for structures such as pergolas.
Wisteria sinensis is best for walls as the shortish flowering racemes are displayed to their advantage.
There’s lots of colours choices with most wisteria now. They are cultivated to be pink, white and varying tones of purples, from the lightest lilac the most vivid violet.