Wisteria: pruning

Wisteria needs regular pruning to keep the growth and size under control, but it will also improve the flowering display. Although it seems complicated, wisteria pruning is quite simple if you follow our simple guide.

Cutting back to two or three buds

Quick facts

Suitable for Wisteria
Timing Twice a year; in Jan-Feb and Jul-Aug
Difficulty Moderate

When to prune wisteria

Wisteria is pruned twice a year, in July or August, then again in January or February.

How to prune wisteria

Wisterias can be left to ramble unchecked where space allows but will usually flower more freely and regularly if pruned twice a year. The removal of growth in summer allows better air circulation and more sunlight to reach the base of the young growths, encouraging better ripening of the wood and improving the chances of flower bud formation. Restricting the amount of vegetative growth and encouraging short, flowering spurs will result in more flowers. 

Summer pruning (July or August)

Cut back the whippy green shoots of the current year’s growth to five or six leaves after flowering in July or August.

This controls the size of the wisteria, preventing it getting into guttering and windows, and encourages it to form flower buds rather than green growth.

Want to see how it's done? Watch our video.

Winter pruning (January or February)

Then, cut back the same growths to two or three buds in January or February (when the plant is dormant and leafless) to tidy it up before the growing season starts and ensure the flowers will not be obscured by leaves.

Want to see how it's done? Watch our video.

Renovation or hard pruning

With older plants severe pruning may be needed to remove old, worn-out growths, or branches growing over windows or protruding outwards from the face of the building. Likewise, hard pruning maybe required where maintenance needs to be carried out on the structure supporting the plant.

Drastically shortening back long branches, removing sections of older stems to just above a strong young branch or growth shoot lower down, or cutting completely back to a main branch, or even to ground level may be necessary. A careful, unhurried approach is needed if larger, thicker branches are to be removed and where a branch is twining it may be necessary to trace back and mark it at intervals with string before removing it. The end result should be a skeleton frame work of reasonably well-spaced branches.

Other points to consider when hard pruning;

  • Hard pruning will stimulate strong, new growth so it is better to avoid feeding in the first spring after hard pruning
  • If there are gaps in the framework suitably positioned new growths can be trained in to form replacement branches, with flowering usually resuming in two or three years’ time. Often there is strong basal shoot growth 
  • If unwanted for replacement branches they can be removed. Any such pruning can be done during the period from leaf fall to early February
  • Other new growths can be pruned back summer and winter as for normal routine pruning

    Summer pruning: New shoots that are not needed or have grown in already crowded areas should be pruned. Cut them back to five or six leaves from the main branch, making the cut just above that leaf.Summer pruning: about two months after flowering, tie in the new, long shoots on to trellis or stout wires.Winter pruning: Long, whippy shoots that grew after the summer pruning should also be pruned. Cut these back to five or six buds from the main branch, making the cut just above a bud.Winter pruning: In January or February shorten summer-pruned shoots further. Cut them back to within 2.5–5cm (1–2in) of older wood, or 2 to 3 buds.

    Other ways to train wisteria

    On walls

    The ideal way to grow wisteria against a wall is to train it as an espalier, with horizontal support wires (3mm galvanised steel) set 30cm (1ft) apart. Over time, and with pruning twice a year, plants will build up a strong spur system. Use new growths that develop near the base of plants as replacement shoots, if necessary, or cut out at their point of origin.

    On pergolas and arches

    Wisterias with long flower racemes are best admired on structures where they can hang free, unimpeded by branches or foliage. For the best flowers, reduce the number of racemes by thinning out to give those that remain plenty of space to develop.

    Growing into trees

    Wisteria can be trained to grow up into the canopy of a small tree, but to the possible detriment of the tree. Growing into large trees can make pruning of the wisteria difficult, and flowering may be affected if the leaf canopy is dense. If you choose to grow into a tree, plant the wisteria on the south side of the tree, 1m (3ft) away from the trunk.

    Training as standards

    Standard wisterias can be grown either as specimens in a border, or in a large pot.  

    • Start with a young, single-stemmed plant, and insert a 1.2-1.5m (4-5ft) stout support next to it when you plant into the ground or container. This will be used to create the main stem of the ‘lollipop’
    • If planting in a pot, John Innes No 3 potting compost is a good choice of compost. Make sure the wisteria is planted to the same depth as it was in its pot from the nursery, spreading out the roots and loosening the root ball before planting. Choose a cheap container that is only slightly larger than the plant needs, potting it on gradually as it grows to fill its final display container
    • Train the stem vertically up the support (this is usually stronger than twining)
    • Allow the plant’s leader to grow unchecked until it reaches the top of the support and then remove the tip in the following February to encourage the formation of sideshoots
    • Prune the sideshoots the following winter, shortening them to 15-30cm (6in-1ft) and repeat this process each winter to gradually build up a head
    • Weak or misplaced growth can be cut out entirely, as can older branches if the head becomes too dense in later years
    • As the head develops, prune in August as well. Cut off above the seventh leaf any shoots that are not needed to extend the head
    • The following February cut back these shoots to 2.5cm (1in) of their bases, just as you would routinely prune a wall-trained plant

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    • IanG avatar

      By IanG on 31/08/2014

      I have a very old Wisteria which had to be cut back to the roots to do major repairs to the wall behind. I thought we had killed it off but it has produced loads of whippy growth which is lying in an untidy mess on the ground. There is no longer a major stem but can I resurrect the wisteria just by taking some of the whippy bits and starting again tying them back to the wall. If so, how many should I tie back and are there any rules I should follow on this? Presumably the rest should just be cut off. Or is there a better way of doing this? Grateful for advice.


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    • Mr G Webster avatar

      By Mr G Webster on 10/08/2014

      In late July I pruned the 'whippy' bits as suggested above, however they are back with a vengeance! What have I done wrong? What do I do now?


    • Mr G Webster avatar

      By Mr G Webster on 10/08/2014

      In late July I pruned the 'whippy' bits as suggested above, however they are back with a vengeance! What have I done wrong? What do I do now?


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    • MaryD avatar

      By MaryD on 08/08/2014

      My wisterias went in the ground over a year ago. They are growing well and over 3m on a pergola but only 1 flowered this year and with less than 6 blooms. Should we prune this summer as per your advice pr leave it another year as they are newish plants?


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    • Margaret Hargreaves avatar

      By Margaret Hargreaves on 28/06/2014

      Most years my Wisteria has lots of flowers, but the blossoms are hidden by lush foliage. How do I reduce the foliage in order to allow the beautiful flowers to show themselves. M.H.


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    • anonymous avatar

      By anonymous on 21/05/2014

      I have noted only one entry regarding someone's Wisteria suffering from the new-ish Wisteria scale. For anyone who needs to know, this has spread out from the reported sites in London. My brother had two beautiful mature specimens but now only has one. We live in Gillingham, Kent. I am hoping to save the remaining plant and will soon be attacking the scale with Provado. Jules.


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    • JerseyLily avatar

      By JerseyLily on 29/04/2014

      Oops, when I wrote the above my comment wasn't appearing on a whole page about pruning wisteria! Now I look like the obvious newbie that I am. :/


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    • JerseyLily avatar

      By JerseyLily on 29/04/2014

      Have you been pruning it twice a year? I ask only because I've only just done this in the last 12 months with ours and the display this year is going to be lovely. (Should be pruned in Jul/Aug and again in Jan/Feb). ~ Sorry if I'm stating the obvious to you ~ ...I'm wondering if your builders have inadvertently done you a favour and after this one year of sulks you'll be amazed at your flower display. I do hope so.


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    • Pat.L avatar

      By Pat.L on 29/04/2014

      I have a Wisteria (which grew as tall as the house) that took 15+ years to flower (mostly at the top). Last year, builders vandalised it, by cutting all the top growth off. Now the 6-8 bare stems (which are about 2-3 inches thick and 10-15 feet long) have all sprouted with foliage along the stems from top to bottom. Will it flower again soon or will we have to wait another 15 years?


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