Last updated on January 22nd, 2020
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Wisteria are an outstanding feature in many English cottage gardens and produce the most beautiful display of flowers during May and June. The draped, petulant, scented blue flowers provide one of the most spectacular show of any climbers. They are loved by both novice and expert gardeners alike.
Before we talk about pruning a Wisteria, we think it is best to talk about what types of Wisteria to buy if you do not already have one. Firstly, never purchase a wisteria that has been grown from seed. Many people get seeds from friends but this will not reward you with flowers, not for at least 20 years in any case. Choose Wisteria that are a more specific cultivar and have been grown from cutting or graphed. Graphed plants are easy to spot as they have a large bulge at the base of the plant.
Pruning Wisteria Guide
Wisteria are a vigorous climbing plant so don’t worry if you prune it incorrectly as they are forgiving and you will get another chance. Wisteria need to be trained on strong wires or on a strong trellis which the branches will be tied to. Wisterias need to be pruned twice a year, once a couple of months after flowering has finished. This is usually around July – August, and it is to control the long shoots and promote this growth to become flowering spurs. Prune again for a second time in mid-winter, around January – February to prepare the spurs for Spring.
Pruning a Wisteria for the first time
For the first 2 or 3 years you need to prune the wisteria to form the permanent frame and shape of the wisteria which will form the main thick stems of the plant that will support the new growth that will be pruned twice yearly.
Year 1 Pruning ideally around July
- Tie the main stem of the Wisteria to the support frame you are growing it up.
- Choose 2 strong side shoots from each side of the wisteria and tie them horizontally onto the support. The two side shoots should be around 45cm apart, one near the bottom and one further up the main stem. In total you will have 4 side shoots.
- Prune off any other branches produced during the growing season and remove any other side shoots between the horizontal branches.
- Prune any side shoots coming from the 4 horizontal shoots you tied, to around 3-5 buds.
Year 1 Prune again in November
- Cut the main central shoot back to around 80-90cm (3ft)
- Tie in healthy side branches and cut them back by around a third.
This first year of pruning will encourage a healthy well-shaped Wisteria which will fit your desired space.
Wisteria Yearly Pruning Guide
Summer Pruning – July – August
Pruning Wisteria in July – August is done after your Wisteria has finished flowering and a couple of months has passed ( Wisteria flower around May -June). Summer pruning is done to reduce growth, allowing more light to reach young new foliage and ripen growth which helps bud formation. This helps encourage more flower spurs and results in more flowers. Simply prune the current years growth back to 5 or 6 leaves and tie in more shoots.
Winter Pruning – Can be done from November but January – February is ideal
Once the plant had lost all its leaves prune the same growth you pruned in Summer back to 2 – 3 buds, this is the growth that will produce that season flowers. You can also cut the main shoots to keep them within your growing area to stop it getting too large for the planted area.
You have now successfully pruned your Wisteria and.should be rewarded with more flowers if done twice, yearly as directed.
Sometimes older plants become worn and can benefit from a hard pruning to replace old side branches with new branches, this pruning should be done after flowering. Simply cut back old branches to the main central stem and find a strong new side branch to replace and tie in. Wisteria can be pruned back very hard, nearly down to ground level if needed. Ideally you want to prune your wisteria so you are left with a skeleton frame work of strong branches.