The most successful way to keep a wisteria from spreading out of control is to prune it twice per year. 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.
How is wisteria kept in check?
Wisteria produces a lovely spring show, but this tenacious vine requires a lot of pruning to prevent it from engulfing the entire garden.
A gardener with the Oregon State University Extension Service named Neil Bell claimed that wisteria are “extremely robust vines and can climb easily to 30 to 40 feet.” They should be grown on a sturdy structure because they can be rather hefty.
People want wisteria for their own gardens after witnessing the beautiful blooms explode in the middle of spring. But they should first be aware that the vine also requires intensive pruning in addition to the right support.
People should be aware of the work required to keep them in check before planting one, Bell advised. “Most flowering shrubs may be pruned once a year, but because wisteria is so incredibly vigorous, summer pruning is also beneficial. The biggest error is not pruning at all.”
The Chinese species (Wisteria sinensis), which blooms on bare branches before foliage emerges with flowers that open all at once, is the one that is most usually planted. They are smaller than the Japanese wisteria (W. floribunda) blossoms, which unfold after the leaves emerge and gradually from the top down. The colors of fragrant flowers range from blue to lavender and, less frequently, white. Both kinds produce a lot of runners, which can be cut back more frequently than twice a year if the plant is in danger of taking over a building, especially your home.
Winter is the best time to prune because the leaf has fallen and the runners are simpler to spot, according to Bell. Examine the vine, trim any extra growth to the trunk, and then trim the remaining runners to two or three buds or a length of about 6 inches. Just above the selected bud, cut. Again in the summer, you should trim any extra growth and leave only two to three buds.
Another choice is to educate your wisteria to grow into a tree, which enables it to develop far from any structures where, if unpruned, it could seriously harm them. When it comes time for cutting, Bell added, it also makes it simpler to maneuver around the plant.
Use a sturdy metal stake to hold the vine to form a tree. It can take one growing season to train one shoot to climb the support, he advised. The basic shape of the tree is finished the next year by cutting the main stem above the top of your support where you want “branches” to develop. After this, the wisteria will require severe trimming every year to stay under control. The shoots can be severely pruned and still produce flowers.
Sometimes wisteria owners lament the lack of blooms on their plants. Be warned that, unless you purchased one while it was in bloom, blooms frequently don’t appear for two or three years (and perhaps longer) after planting. However, there are several things you may do to speed it up if you’ve waited for what feels like too long. Root pruning and stressing the plant by not fertilizing it will frequently force it to bloom. To root prune, cut the roots in a circle one to two feet from the plant’s trunk using a shovel.
Other growth advice from Bell for wisteria includes planting in full sun and maintaining continuously moist but not soggy soil. Use a low-nitrogen fertilizer (first number in the three-number label sequence). Less fertilizer is preferable to excessive fertilization. Feeding should only occur once a year, every other year, or never.
Fun fact: Sierra Madre, California is home to the largest known wisteria, which is over 1 acre in size and 250 tons heavy. In 1894, the Chinese species was planted.
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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.
What are wisteria runners used for?
Trim them back to 2 to 3 buds or 2.55 cm (12 in) of older wood. Summer pruning: Remove any new shoots that are unnecessary or that have grown in congested locations. Make the cut directly above that leaf, then trim them back to five or six leaves from the main branch.
What naturally eliminates wisteria?
Starve it to death With this technique, the wisteria is simply trimmed back and pulled up repeatedly until it dies. After getting rid of all the vines above ground, you must starve the roots of sunlight in order to destroy them.
How may wisteria roots be stopped from growing?
Wisteria is not the best option if you want a compact, low-maintenance shrub. Nevertheless, reducing it to a manageable level only requires work a few times every year. The key to maintaining Wisteria is routine pruning, but there are other techniques to keep it in check as well.
Prune, Prune, Prune!
Twice a year, in late winter or early spring and mid-summer, wisteria is typically clipped. You can avoid using the summer pruning if your wisteria isn’t too vigorous. Prune your wisteria frequently throughout the summer if it is growing too quickly or if you want to keep it in a formal shape (in addition to the winter prune).
To prevent new shoots from becoming too long, prune throughout the summer. Over the course of the summer, you’ll notice that your wisteria is growing more and more shaggy. It is these whippy shoots that need to be pruned down. Once the blossoming is through, you can choose to prune as frequently as you’d like throughout the summer, or simply once.
Cut down the new growth to around six inches when pruning in the summer, and entirely remove any undesirable shoots. Large runners on the ground should be pruned since they have the potential to grow their own roots.
Pruning should be done more ruthlessly in the winter. After the coldest days have past but before the sap rises and the buds begin to emerge, is when the conditions are ideal. Cutting out half of the summer’s new growth is the easiest approach to prune in the winter.
Winter is the best time to focus on the shape of your wisteria and regulate its size by eliminating unnecessary branches and trimming the shoots you wish to keep to size. You can determine how much to prune by counting the buds; unless you want to totally remove a branch, leave two to five buds on each stalk.
During your winter pruning, trim your wisteria to a size that is somewhat less than you desire if you don’t want it to grow any larger. Otherwise, once it starts to develop in the summer, it will be bigger than you want.
You should be aware that severe pruning can lessen the number of spring blossoms you observe. While trimming might encourage blooming, if all the buds are removed, no flowers will appear. For the best blossoming, you should leave two or three buds on every new growth.
If your wisteria is already out of control and needs to be severely pruned, I’ll go over a hard prune in more detail below. Wisteria should be pruned regularly and annually to maintain the desired size and shape. The focus is on prevention.
With more detailed step-by-step directions, we have an article that covers all the ins and outs of trimming wisteria. How to Prune Wisteria: When, Where, and Why can be found here.
Deadhead or Remove Seed Pods
Wisteria spreads primarily through three different mechanisms: runners, which spread out and take root, new shoots emerging from the root system, and self-seeding with its eccentric popping seed pods. By removing the seed pods before they release the seeds or by preventing the wisteria from going to seed in the first place, the last of these is simple to control.
After drying out in the fall, wisteria seed pods explode, ejecting seeds in all directions. After a cold spell, the popping usually begins on a warmer day. It is best to remove the seed pods from your wisteria before they dry out in order to prevent the plant from spreading its seeds.
Deadheading is the method to use if you’d rather prevent the wisteria from producing seed pods in the first place. Deadheading, which is the act of removing wilted blossoms from a plant, has advantages besides limiting the development of seeds. If your Wisteria isn’t covered in dead flowers once blooming is finished, it will appear nicer. Deadheading might boost blooming.
Deadheading can begin as soon as the flowers begin to wilt. Simply use your pruning shears to cut each cluster of spent blossoms off.
Wish to learn more? Here you may read more about wisteria seed pods and discover all there is to know about deadheading wisteria.
Monitor for Shoots
Pulling up new shoots that emerge from the root system is an additional method to prevent Wisteria from getting out of control. Wisteria often has a huge root system to support its bulk, and those roots have the ability to sprout what appear to be new Wisteria plants even though they are connected underground.
Pulling up shoots as soon as you notice them is the best approach to control them. They can also be sprayed. Alternatively, if they are on your lawn, mowing may be sufficient to keep them in check.
If your wisteria is seriously out of control, consider walking your property once a week to look for new shoots and pulling off any you find. You’ll rapidly become adept at identifying them.
Keep Wisteria Away From Trees and Buildings
If you let wisteria to climb trees or walls, it will quickly outgrow your control because of how much it enjoys climbing. Once the vine’s top is hidden from view, it is less likely that you will detect where the shoots are growing. A large ladder must also be dragged outside before pruning.
Wisteria may harm both trees and buildings. Growing vines can damage subterranean pipes, suffocate trees, and rip off roof tiles or shutters. Although wisteria appears lovely when it covers the walls of old-world houses in masses of blossoms, keeping it that way without causing harm to the house requires a lot of labor.
Train It As A Standard
Growing Wisteria as a tree is a fantastic strategy to keep it compact and controllable. Wisteria can be trained to take on the shape of a tree, even though there is no such thing as a Wisteria tree in nature (this is called a standard).
If you grow your Wisteria as a standard, you will still need to prune it, but the shape of the tree makes it simple to identify runaway shoots. Wisteria is easy to manage because it grows in a smaller plant thanks to this method of cultivation.
You require a strong stake to support the wisteria in order to grow it as a tree “trunk. Select one of the major vertical shoots to serve as the trunk, and allow it to continue to develop until it reaches the desired canopy height (a few feet). then cut the off the “To promote branching into a canopy shape, place a trunk at the top.
Like other Wisteria, Wisteria trees need to be pruned at least twice a year. Manage the canopy’s size and shape, get rid of suckers, and prevent new shoots from sprouting from the trunk.
Check out this page for detailed instructions on how to train a wisteria tree if you’re interested in growing one.
Grow It In A Pot
Another fantastic method for controlling Wisteria is container planting. The root system won’t spread out all over the place, and wisteria doesn’t get as big in a container as it does in the ground.
Remember that potted Wisteria need daily watering, frequent fertilizer feedings, repottings, and root cutting on occasion. Find out more about container-grown wisteria here.
Choose American Wisteria
The Chinese Wisteria type is the one that is most frequently offered for sale at garden centers, although there are other, less aggressive, options. Because they are simpler to manage, American Wisteria cultivars are becoming more common.
Additionally, American and Kentucky wisterias are indigenous species that nourish wildlife and won’t harm the ecosystem if they escape from your yard if you live in the Eastern US. I adore Kentucky Wisteria personally. Kentucky Wisteria is just as beautiful as Asian Wisteria while being easier to care for. American Wisteria has smaller flower racemes and isn’t as fragrant.