A question that gets asked regularly within our shop is ‘why doesn’t my Wisteria flower?’. I hope that this guide offers some help in the matter and shows that it is crucial to prune twice a year to encourage flower.
Pruning a Wisteria should be carried out twice per year. Two prunings per year not only helps in the development of flowers, it also keeps the Wisteria in check; they can be incredibly invasive plants if left unpruned Mid to late winter, is one of the times in the calendar when the pruning should be done. Pruning is then carried out again during July.
If the pruning is not carried out correctly the plant produces too much vegetative wood at the expense of flowers. Unless they are being used to extend or improve the framework, the vigorous young vegetative shoots need to be strongly curtailed to encourage flower production. The plant’s energy needs to be diverted into producing flowers and this is best achieved with pruning. If you intend to prune a very neglected, twisted and totally out of control Wisteria, some pruning of the very woody older stems may be required, but under normal circumstances, this older wood, that forms the framework of an established Wisteria is left unpruned. Regardless of what is going on with the older stems, which are often intertwined and difficult to prune, the main aim is to get the younger shoots that are easy to work with growing in a horizontal row formation along the space you have to fill. This will create the correct framework shape for future years. It is off these horizontal stems that shoots with the potential to develop flower spurs will be produced and if pruned properly and at the correct time of year they will produce a good show of blooms.
Use the following steps to prune your Wisteria: Identify the stems that form the framework of your Wisteria. Do not cut or prune any of these unless you need to start afresh with the training because the framework shape is incorrect. Have a definite picture in your head of how the Wisteria should look in years to come, it should have a central upright stem, (or realistically a plat of several mature upright stems) off which mature horizontal laterals produce the flower-bearing shoots. Wisteria flowers are more likely to be produced on short spurs originating from horizontal shoots. It is only the younger, greener more flexible vegetative shoots that need to be pruned if the woody framework already has the correct shape. The young green shoots are often out of control and can grow up to 4 metres in a single year. With each young green shoot, decide if it is to be kept, to be tied in as a new horizontal framework shoot. As you choose the new horizontal framework shoots they should be tied onto strong horizontal wires. If you decide that the young shoot is not required as a new framework shoot, it can be converted into a flower bearing spur. Trace it back to the horizontal shoot from which it originates and cut it back to 2 or 3 buds after the point at which it protrudes, leaving a short spur. Pruning these shoots in this way encourages the short spur to produce flowers. Then in July, after flowering, cut back the same shoots again, but this time not so short; 5 or 6 buds in length. This second pruning allows more light and air to be absorbed by the older woody framework, encouraging it to ripen and therefore develop more flower buds. Wisterias do need twice as much pruning as most other climbers, but your hard work will be rewarded; there is no finer sight in horticulture than a well pruned Wisteria in full bloom during early summer.
Looking for a spectacular climber to cover a wall or arbor? Fast-growing wisteria could be the answer.
Wisteria is the quintessential climber for the English cottage garden. A well-grown wisteria is an absolute joy in May and June when the beautiful, scented pendants of flowers drape from the branches in a breathtaking display. But often gardeners find these climbing plants a little daunting. The idea of all that pruning and training just feels far too complicated. It’s a shame because it’s not as tricky as you might think – in fact wisteria is actually very easy to grow. With correct care these long-lived twining climbers will reward you with many years of pleasure in your garden.
Location is in important factor to consider when growing Wisterias. They are long lived and will form woody stems over time which require significant support. This makes them very difficult to move if you change your mind in a few years time. Also bear in mind that they require regular pruning to keep them under control and to encourage flowering, so it’s well worth taking your time to choose the best possible location for your plant. Location is an important factor to consider when growing Wisterias. They are long lived and will form woody stems over time which require significant support. This makes them very difficult to move if you change your mind in a few years time. Also bear in mind that they require regular pruning to keep them under control and to encourage flowering, so it’s well worth taking your time to choose the best possible location for your plant.
Prior to planting add plenty of well rotted manure or garden compost to the soil to improve soil fertility and drainage. Remember that your wisteria will be planted here for many years so it’s worth taking the time to create ideal soil conditions from the start. Plant wisteria at the same level that they were supplied in their pots. If you are planting a bare root wisteria then look for a soil mark towards the base of the stem which indicates what depth it was planted in the ground at the nursery. This is usually found a little below the graft point – a bulge in the stem where the main plant is grafted to the rootstock. Water your wisteria well after planting to settle the soil.
During their first year wisterias will benefit from regular watering while the roots establish. Once established Wisteria should only need supplementary water during dry periods. A high potash feed can be applied in spring to help encourage flower production but don’t overdo it as over-feeding wisteria can cause more foliage and less flowers.