Last updated on January 24th, 2022
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Wisteria creates an outstanding feature in many English cottage gardens and produces the most beautiful display of flowers during May and June. The draped, petulant, scented blue flowers provide one of the most spectacular shows 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 anyway. Choose a Wisteria that is a more specific cultivar and has been grown from a cutting or grafted. Grafted plants are easy to spot because they have a large bulge at the base of the plant.
Pruning Wisteria Guide
Wisterias are vigorous climbing plants so don’t worry if you prune them incorrectly as they are forgiving and you will get another chance. Wisteria needs to be trained on strong wires or on a strong trellis to which the branches will be tied. Wisterias need to be pruned twice a year, once a couple of months after flowering has finished. This is usually around July – August 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 will need to prune them to form the permanent frame and shape of your Wisteria. These will form the main thick stems of the plant, which 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 that 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 (Wisterias flower around May -June). Summer pruning is done to reduce the growth, allowing more light to reach the young new foliage and ripen growth that helps with bud formation. This helps to encourage more flower spurs and will result 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 back the same growth you pruned in the Summer down to 2-3 buds, this is the growth that will produce that season’s flowers. You can also cut the main shoots to keep them within your growing area to stop them from getting too large for the planted area.
You have now successfully pruned your Wisteria and you should be rewarded with more flowers if done twice, yearly as directed.
Sometimes older plants become worn and can benefit from 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 that you are left with a skeleton framework of strong branches.