How And When To Trim Wisteria

Pruning wisteria twice a year is the best approach to prevent it from growing out of control. After the flowers have faded in the early to mid-summer and when the shoots from this year’s growth begin to look untidy, the first pruning should be done. The goal is to remove undesired shoots or suckers and to keep new development close to the main vine as follows:

  • Trim fresh growth shoots to a length of 6 inches.
  • Suckers at the roots should be removed.
  • Cut off any sprouts that the vine’s main support structure doesn’t require.

Since flowers only appear on one-year-old growth, this pruning strategy not only keeps the vine in a tight shape but also enables the blooms to be seen the following year.

Can wisteria be severely pruned?

If the wisteria plant has a lot of dry, old branches and appears to be highly out of shape, it can be severely pruned back.

In order to renovate the plant, it is occasionally necessary to remove every branch, all the way to the main stem or even to the ground. Your wisterias will be inspired to grow new, robust branches as a result of this severe trimming.

McKenzie cautions that while the growth will be of much superior quality, the wisteria may not blossom for two or three years following a hard cut back.

A new pergola or arch can be created by “hard pruning” in addition to retraining the plant.

Does wisteria require pruning?

So let’s get started. When should wisteria be pruned? Wisteria should be pruned once in the winter and once more in the summer. You should prune your wisteria in the summer approximately two months after it blooms.

In order to properly trim a wisteria, you must first understand that regular pruning is necessary to regulate growth and promote more blossoms. The current season’s shoots are pruned back to three buds from the root. The new shoots and blooms for the upcoming season will then emerge from these buds.

Wisteria that has grown too large can also be pruned. The best way to trim the wisteria in this situation is to lop and cut as much as you like, down to around 3 feet (1 m), or where you truly want the wisteria to be. In this manner, you will have lovely new shoots the next spring as new sprouts appear and it develops to that height. When you prune wisteria in this way, keep in mind that doing so will prevent any flowering for several years as the new shoots mature once more.

You’ll discover that trimming the wisteria may have caused some of the larger branches to die back. This is fine. You can simply remove them from the plant or completely prune them back. It occurs. You cannot change the situation much, unfortunately. Have no fear. The plant won’t die as a result.

When it comes to wisteria trimming, there are occasions when some people believe that persistent wisteria cutting, especially if it hasn’t bloomed in a while, will eventually cause an older wisteria bush to bloom. Though it might be worth a shot, this might or might not be true. Wisteria can generate new growth as a result of trimming, and the flowers will eventually appear on this growth. Your aim might only be accomplished after a few years.

Some people think that cutting the roots with a shovel is the best approach to trim wisteria, especially an older one. According to them, doing so actually aids the plant in absorbing more nutrients from the soil and finally blooming. Again, because you most likely cannot kill it, feel free to try this approach as well!

How should a wisteria tree be maintained?

My initial apartment search in Brooklyn led me to a one bedroom on a peaceful, tree-lined street. The flat itself wasn’t memorable, but the structure was: The entire brownstone was encased by an impenetrable mass of wisteria, windows and everything. Covering a three-story building is no issue for some powerful wisteria vines, which are able to grow 10 feet or more in a single season. Yet for all its uncontrolled activity, a wisteria in full bloom is one of the finest views.

Wisteria may happily twine, climb, and sprawl over anything in its path for a very long time without any pruning. But a trimming routine becomes an essential task for the gardener who has a small yard and wants to enjoy more obvious and many wisteria flowers. Plan on pruning at least twice a year (once in the summer and once in the winter) for best results. Knowing how the vine grows will also aid in your success.

Not everyone prefers to live without windows, but no one needs to if they plan ahead and make a commitment to routine pruning.

Summer: Cut the long shoots after flowers fade

Since wisteria flowers grow on the growth from the previous year, pruning wisterias twice a year not only keeps them in controllable proportions but also develops a network of short branches close to the building so you can more readily enjoy the blooms. Simply cut the long branches from the current year’s growth back to 6 inches in length in the early summer after the vines have flowered to achieve this. Pruning away root suckers, especially on grafted kinds, and totally removing any branches not required for the main framework of the plant should also be done at this time. Depending on how much time you have and how tidy you want your vine to look, you could choose to prune this way once or more regularly during the summer. Remember that wisteria seedpods are ornamental to many gardeners, so you might wish to leave some wasted blossoms remain.

Design Tip

For winter interest, some seedpods may be left on the vine, but if you bring them inside, high temperatures will force them to explode. The pea-shaped fruit was once utilized by a friend as part of a winter arrangement. The following morning, she discovered her cat hiding in a corner from the flying seeds.

Winter: Prune long shoots down to three or five buds

Trim the long stems that have sprouted after the summer trimming to three to five buds in the late winter. Remove any undesired long shoots from the previous season as well; they will be easier to spot now that the framework is leafless.

To focus energy on flower production rather than vegetative development, even short branches should be pruned to three to five buds.

Why your wisteria may not bloom

Wisterias are infamous for not blooming. Make sure these fundamental cultural prerequisites are satisfied before attempting severe measures.

The decision to go with a seed-grown plant rather than a grafted plant is the most frequent cause of a lack of flowers. While seed-grown vines may take up to seven years before flowering, grafted plants normally blossom within three years.

High winds and late frosts can harm flower buds, particularly those of Wisteria sinensis. Wisteria, on the other hand, blooms best following years with hot summers.

Avoid fertilizer with a high nitrogen content. Wisteria fixes nitrogen in the soil like other legumes do. A surplus of nitrogen might result in poor flowering and excessive leaf growth.

Training a new wisteria on a pergola

The plant’s strength allows it to adapt to various forms. Wisteria can be trained against a structure or lattice, molded into a shrub or standard, or planted on a pergola or arbor. Because of its long blossoms, which dangle dramatically through the top of pergolas and arbors, wisteria floribunda is a popular choice. Since it grows so quickly, like other wisteria species, only one plant is typically required to completely cover a structure. However, placing two vines at the opposite ends of a structure provides it aesthetic balance and allows a gardener to showcase two different cultivars on the same structure.

Planning is essential when training wisteria to grow on a pergola or arbor. These constructions must be fashioned of a sturdy, weather-resistant material, such as cedar, and properly anchored in the ground with concrete footings in order to be used effectively. Don’t be scared to overbuild a pergola or arbor because wisteria is notorious for tearing down its supports. I suggest using at least 24 lumber for the crosspieces and 44 lumber for the posts.

Allow two or three young shoots to knot loosely around each other and the post as they grow to start training a new plant onto a pergola or arbor. Since the woody stems grow gnarled and attractive as they mature, this will help give interest to the plant’s structure. As they climb, the young shoots need to be fastened to the post. To do this, fasten a 14-gauge galvanized (or comparable) wire to the post using eye hooks spaced roughly 18 inches apart (or on all four sides for extra support). Use gardening twine to secure the shoots to the wire as they develop. As they develop, give them some breathing room to develop a more attractive habit and avoid having them mature and put a lot of stress on the framework.

The shoots should be headed back (their tips should be pruned) once they have reached the top of the arbor to encourage side shoots that will spread across the tops of the supports and bear flowers. The training ties on the post will no longer be required as the plant matures and becomes more stable across the top of the structure. In order to keep the plant from becoming girdled as it grows, it is a good idea to remove them.

How are overgrown wisterias pruned?

A wisteria that has been let to grow out of control can frequently produce a tangle of dead, malformed branches that may or may not flower. It could take up to a year of trimming and pruning to transform a wisteria into a blossoming vine that is manageable in size. The steps are as follows:

  • Cut back withering and dead branches to the nearest sound tree.
  • Reduce suckers at the base so that only one or two primary stems remain.
  • Eliminate overgrown lateral branches that sprout from the main trunk.
  • After flowering, trim the remaining lateral branches.
  • If the vine is excessively long, trim the top of the main trunk to 4-6 feet, or the desired length.

Once your wisteria has recovered its shape, continue to prune it twice a year to maintain the desired size. You can prevent your wisteria from growing out of control and get the most blossoms each spring by regularly cutting it.

Does ancient wood allow wisteria to bloom?

In the preceding growing season, Wisteria generates its flower buds (“blooms on old wood”). Those buds were taken out if the plants were clipped from late fall to early spring.

How can wisteria be kept in check?

Wisteria may swiftly and easily suffocate nearby plants and other structures in its path if you don’t know how to control it. Although wisteria pruning is not difficult, it might take a lot of time. However, wisteria can only really be kept in check by aggressive pruning.

Throughout the summer, you should regularly prune the wisteria to remove any stray shoots as well as any new ones that may emerge. Also in the late fall or winter, give the wisteria a thorough pruning. Cut rear branches from the main trunk about a foot (0.5 m) away after removing any dead or dying branches. Any suckers that may also be present close to the base should be found and eliminated.

Should wisteria be deadheaded?

Wisteria pruning is relatively simple, but it’s necessary if you don’t want it to spread beyond its designated area each year.

This can happen whenever the plant is dormant, from the moment the leaves have dropped to the conclusion of the winter.

  • It’s crucial to just eliminate new growth to promote flowering because flowers grow on the growth from the previous year.
  • Trim lateral branches in the winter, leaving only one or two buds.

This is to leave the main branch alone and to prune all of the stems that grow from it.

  • Because the fruits of wilted flowers are poisonous, remove them frequently (deadheading).

How should wisteria be maintained in the winter?

Let’s start by stating that winter care for wisteria is not actually required. The tough plant wisteria can withstand a variety of harsh weather conditions. Wisteria can overwinter without additional work unless it was recently planted or was unwell. If you have the time to give a healthy wisteria a little additional care to winterize it, that’s fine, but if you don’t, don’t worry about it. Giving your wisteria a little more attention in the winter helps keep it healthy whether it was recently planted or had issues the previous year.

Mulching the plant’s base to provide the roots additional protection and clipping away any dead growth you may find on the plant are two general additional winter maintenance procedures for wisteria. You can also shape the wisteria vine with cosmetic pruning if it’s late fall or early winter (after the plant has shed its leaves but before snow has fallen).

If your wisteria has previously struggled to bloom, there’s a potential that the plant may be experiencing winter dieback, which destroys the blossom buds. If you have reason to believe this is the case, you can aid the blossom buds by wrapping the plant in burlap. This step is not necessary if your wisteria has blossomed successfully in previous years. Please keep in mind that wisteria only experiences winter dieback in extremely cold climates. There are more likely causes for your wisteria’s lack of flowering if you do not reside in an extremely cold climate.

Really, this is all that is required to care for wisteria in the winter. The wisteria will survive the winter without the extra care even if you realize that other tasks in your yard are more urgent and you do not have time to winterize it.