It is well known that wisteria take a very long time to bloom. For two to three years after planting, don’t anticipate blossoms. Some readers swear by the following technique to encourage blooming:
- To cut into part of the roots, take a shovel and drive it 8 to 10 inches into the ground approximately a foot and a half away from the main trunk of the wisteria.
- Approximately half of the roots should be damaged for the shrub to be shocked into reproduction (flowering).
- Don’t worry—impossible it’s to harm this unchecked, unwieldy, frequently invasive shrub!
- The flowers of wisteria can also be impacted by chilly winter temperatures.
Native Wisteria
Consider growing a wisteria species that is indigenous to North America if you live there, such as:
- Wisteria frutescens, also known as American wisteria, thrives in zones 5 through 9. Its original states span from Virginia to Texas, the southeast to Florida, and up into New York, Iowa, and Michigan in the north. The vine is 25 to 30 feet long, has glossy, dark-green leaves, and after the plant has begun to leaf out, develops huge, drooping clusters of lilac or purple-blue flowers. Only new wood will display the blossoms. Notably, the blossoms are typically less aromatic than those of Asian wisterias.
- In zones 4 to 9, Kentucky wisteria (Wisteria macrostachya) flourishes. Similar to American wisteria, this late-bloomer is a native of the Southeast of the United States (it is sometimes considered a variety or subspecies of American wisteria). The Kentucky wisteria is the quickest to blossom, bearing faintly fragrant bluish-purple flowers after only two to three years of growth.
- A gorgeous, silvery-blue cultivar of the native Kentucky wisteria called “Blue Moon” is particularly hardy. In late spring or early summer, it blooms. It can go as chilly as -40F. (-40C).
Non-Native Wisteria
- Despite the fact that they are frequently marketed at nurseries and garden centers, Chinese wisteria (Wisteria sinensis) and Japanese wisteria (Wisteria floribunda) are non-native, invasive species, hence we do not suggest them for North American gardens. They can reach lengths of 30 to 60 feet and are hardy in Zones 5 to 9. (and beyond in the Southern U.S.). Japanese wisteria comes in two popular kinds, including:
- Popular plant known as “Honbeni” displays clusters of pink flowers in the late spring.
- “Alba” (also known as “Shiro Noda”) yields beautiful clusters of snow-white flowers in the late spring.
Are Wisteria Toxic to Pets and Humans?
Yes, the wisteria plant contains lectin and wisterin, which are poisonous to people, animals, and even pets. If taken in significant quantities, these poisons can result in anything from nausea and diarrhea to death.
If pets or young children frequent the area, it is a good idea to remove the seedpods after the plant has flowered because the material is particularly concentrated in the seeds and seedpods. Unaware children or animals won’t think twice about eating as many seedpods as they can because they are not unpleasant to taste or have an instant effect. In case of ingestion, contact your neighborhood poison control center.
The ideal places for wisteria to grow.
According to Kirsten Coffen, a landscape architect and designer based in Maryland, “its gorgeous spring-blooming cascade of purple (or white) scented flowers is best observed when trained on a structure, such as a robust pergola.”
Such a lush, floral canopy offers delightful shade throughout the sweltering summer months. According to Irene Kalina-Jones, a landscape designer at Outside Space NYC (opens in new tab), “We plant it on rooftops in the city, training it to cover pergolas to create shade.” “But I enjoy it grown against buildings, too,” you say.
Wisteria grows best in full sun in a protected location, such as a south or west-facing facade. When planting, work in a lot of organic matter (such as compost) to ensure that the soil is rich and well-drained.
If you want to grow wisteria up a wall or the front of a house, put some effort into building a strong structure that it can climb over many years. A tensioning system of wires is possibly preferable to a wooden trellis because wood can rot. The wires must either automatically tighten as the plant gains weight or be simple for you to tighten (via turnbuckles, for instance).
Where can wisteria be found?
Wisteria (Wisteria floribunda) is a never-to-be-forgotten sight in late spring with its long, hanging clusters of blossoms. Wisteria floribunda is one of many wisteria species that can be found growing in the United States, and it is hardy in USDA plant hardiness zones 4 through 9. Wisteria sinensis is another kind, a slightly more delicate shrub that can survive in USDA zones 5 through 9. Wisteria sinensis and Wisteria floribunda, however, are invasive in several states. Verify that a wisteria vine is not invasive in your state and that it can withstand the coldest winter temperatures and hottest summer temperatures in your hardiness zone before planting it in your yard.
Where shouldn’t wisteria be grown?
In order to support the massive vine, the wisteria’s root system extends out widely and dives deep. Do wisteria roots exhibit aggression? Yes, wisteria’s root system is highly aggressive. Avoid planting wisteria next to walls or walkways because of its extensive and strong root system. These are easily harmed by a wisteria’s root system.
Experts advise inserting a corrugated panel about 6 feet (1.8 m) long and several feet (1 m) broad beside the plant to redirect the roots if you find a wisteria close to a building or pathway.
What degree of heat can wisteria withstand?
Wisteria species also exhibit a wide range of behavior. One of the finest methods to manage this plant is to get off to the right start. American and Asian versions are available. The Asian people appear to be the more exuberant and likely to get out of control of the two. See the illustrations below.
Asian Wisteria
- Japanese wisteria vines like the Wisteria Floribunda can reach heights of 30 to 60 feet. In ideal circumstances (i.e., in the southern US), it may even grow taller.
- Late April sees the blooming of headily perfumed pink blossoms on the exquisite wisteria variety Honbeni or Honko.
- Late spring flowering Shiro Noda or Alba produces massive flower clusters of brilliantly white blossoms.
Although these varieties of wisteria are not native to the US, they flourish in great numbers here. You should plant and keep an eye on these kinds carefully because they appear to be very easy to become invasive and are hardy in zones 5 to 9.
American Wisteria
Some American varieties of Wisteria (Wisteria frutescens) don’t act like invasive species. This cultivar is indigenous to several states in North America. It produces lots of purple, blue, or lilac blooms together with dark green foliage.
The blossoms of this plant only appear on new wood, unlike their Asian cousins, and have no perfume. It can reach a maximum length of 30 feet and is hardy in zones 5 to 9.
Another native American plant, Kentucky Wisteria, thrives in zones 4 through 9. It resembles American Wisteria quite a bit. Furthermore, this type blooms earlier than any other since it establishes very effectively after only a few years.
A cultivar of Kentucky Wisteria with silver or blue blossoms is called as Blue Moon. Both in late spring and again in the summer, Blue Moon blooms. It is from a particularly hardy type and can withstand low temperatures of up to 40 °F (under zero °C).
Types of wisteria:
There are two varieties of wisteria: Asian and American. Although aggressive growers, Asian wisterias are well-known for their stunning blossoms. American wisterias are less aggressive and still produce beautiful blossoms. Compare the most popular wisteria varieties.
Flower color:
Wisteria comes in a range of colors, such as white, pink, and blue tones, in addition to the well-known purple blossoms. If you believe you have seen a yellow wisteria flower, it was probably a golden chain tree (Laburnum).
Foliage:
Wisterias are deciduous, which means that when the weather becomes chilly in the fall, they lose their leaves. The misunderstanding is occasionally brought on by a different vine known as evergreen wisteria (Millettia reticulata).
Avoid planting aggressive wisterias close to your home as they can cause damage and have even been known to destroy buildings.
Wisterias can be grown in full sun or partial shade, but to promote healthy bloom development, make sure the vines get at least six hours of direct sunlight everyday. If you reside in a colder area, pick a planting location that is protected because a heavy spring frost can harm the flower buds.
Create a planting hole that is the same depth as the plant and twice as wide, then level the plant with the soil surface. Because the vines will soon fill in, you should space your plants at least 10 to 15 feet apart along the support structure.
Wisterias don’t need much care once they are planted to promote healthy growth. Water frequently over the first year until the roots take hold.
After planting, wisterias could take some time to come out of dormancy and might not start to leaf until early summer. They will leaf out at the regular time the following spring, but don’t be surprised if they don’t bloom. Wisterias take three to five years to reach full maturity and may not start blooming until then.
Wisterias grow quickly and can reach heights of up to 10 feet in in one growing season. That works out well if you need to quickly cover a fence or pergola but don’t want the vines to take over your landscape. Regular pruning (once in the summer and once in the winter) not only controls wisteria’s growth but also encourages more robust flowering by creating a framework of horizontal branches and causing spurs to grow at regular intervals.
Cut back the current year’s growth to five or six leaves in July or August, or roughly two months after the plant flowers, to get rid of stray shoots and make short branches that will produce flowers the following year. Summer pruning needs to be done more frequently. Re-prune the plant in January or February while it is dormant by removing two or three buds from the growth from the previous year.
The first few years of wisteria’s growth are crucial for creating the desired framework for the plant’s development. As soon as your wisteria begins to grow, start connecting particular lateral shoots to its support structure. You should also cut down any extra growth. An aggressive pruning may be required on elder plants to promote the growth of new branches. Cut down aging branches to the main primary stem to accomplish this. The spaces will soon be filled with new side branches that can be connected back into the support structure.
Visit the Royal Horticultural Society to view a video on how to prune wisteria vines properly.
How does a wisteria look in the colder months?
Don’t panic if your wisteria begins to drop its leaves in the fall. Deciduous wisteria predominates. Winter doesn’t keep it green, but the leaves will come back in the spring.
Before dropping their leaves, some wisteria varieties put on a show of fall color as the leaves turn yellow or gold. If it’s happening in the fall, there’s typically nothing to worry about unless you’re also observing other symptoms like an insect infestation. Yellowing and dropping leaves can be signals of disease and other problems.
While Evergreen Wisteria (Millettia reticulata) is more challenging to grow, all true Wisteria are deciduous. Your Evergreen Wisteria will most likely maintain its leaves throughout the year if you have hot summers and brief, mild winters with little below freezing. This is zone 9b and higher in the US, which includes a portion of California and Arizona as well as the southern half of Florida and Texas.
Evergreen Wisteria is deciduous like regular Wisteria in more temperate regions, so you may anticipate it to go dormant for the winter and sprout new leaves in the spring. You probably won’t be able to cultivate Evergreen Wisteria in a location that is colder than USDA zone 8 because even deciduous habit cannot shield it from prolonged, bitterly cold winters.
Wisteria is resistant to freezing.
Although wisteria is usually resistant to frost, it can nonetheless suffer harm from it to bloom buds and newly budding flowers. When the vine emerges from dormancy and is about to blossom, this can become a concern during late spring frosts.
Wisteria is a cold-tolerant plant that can endure frost, snow, and even extremely low temperatures in some cultivars. Wisteria, on the other hand, emerges from its latent state after the winter and starts to bloom and grow new leaves. It can be extremely harmful to the plant if a sudden cold snap causes temperatures to drop too low.
Because of this, it’s a good idea to plant your wisteria close to some wind protection, like a brick or block wall that retains heat during the day and releases it at night. To get the most sunshine, plant wisteria in a location that faces west or south.
In the first year or two of growth, your wisteria is more susceptible to frost and cold damage. Young plants might not be able to withstand these subfreezing temperatures because they are too delicate. New growth might be vulnerable to frost damage even on established plants.
If you prune your wisteria too late in the growing season, this could happen. As fresh, vulnerable vines and tendrils may develop and not have enough time to harden off before temps fall below freezing, pruning might stimulate new growth at the wrong moment. By avoiding pruning Wisteria plants at any time in the late summer or fall, you can prevent this issue.
Use plastic tubing, bubble wrap, or fabric such as burlap to shield your wisteria from late spring frosts or chilly winds. Plastic tubing is a wonderful alternative because it can be wrapped around the plant’s main vine without the need to attempt to cover a large trellis.
An additional choice is to stake the vine and hang a drop cloth or other fabric over it, covering the entire plant. Just keep in mind to take the cloth off as it warms up over the day. Before a frost, covering your plant will help protect its buds, prevent growth from being stunted, and prevent damage to the roots and vine.
How long does a wisteria live?
A perennial vine known as wisteria bears gorgeously scented blossoms, frequently lavender, that develop in clusters resembling grapes.
However, the wisteria that is widespread in the Southeast is actually an invasive species from China. Chinese wisteria spreads so quickly that it eventually engulfs neighboring plants, shades them out, and even kills trees.
Due to its unchecked growth and capacity to flourish in a variety of environments, Chinese wisteria (Wisteria sinensis) has the propensity to harm regional ecosystems. While Chinese wisteria prefers rich loam and needs sunlight to produce its distinctive blossoms, it will still thrive in shadow and can survive a variety of soils.
Wisteria has the ability to climb up tall trees and will continue to spread over the tree canopy, shading out nearby smaller trees and plants. Additionally, wisteria plants can live for more than 50 years. This longevity only boosts wisteria’s capacity to spread and suffocate local plant life.