Wisteria frutescens, often known as American wisteria, is a twining, woody, deciduous vine that can reach a height of 40′ or higher. From Virginia to Illinois south to Florida and Texas, it is mostly endemic to damp thickets, swampy forests, pond margins, and stream borders.
Where does wild wisteria grow?
In the spring, wisteria blooms ferociously, producing clusters of lilac-colored flowers on fresh growth that develops from spurs off the main stalks. Check out our Wisteria Growing Guide for more information on wisteria maintenance, including planting and pruning.
About Wisteria
Wisteria is a long-living vining shrub with cascades of blue to purple blossoms that, in the spring and early summer, look stunning hanging from a pergola or archway. However, this vine is known to grow fairly heavy and to grow quickly and aggressively, frequently reaching lengths of more than 30 feet. It’s advised not to put wisteria vines too close to your home since they will squirm their way into any crack or crevice they can find.
Beautifully fragrant wisteria flowers offer a feast for the senses. A brown, bean-like pod remains on the plant during the winter after flowering. There are only blooms on fresh growth.
Note: Be careful when planting wisteria! 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.
Is Wisteria an Invasive Plant?
The wisteria species Wisteria sinensis and Wisteria floribunda, which are not native to North America, are regarded as invasive in several areas. If you want to add a new wisteria to your garden, we advise choosing one of the native North American varieties, such as American wisteria (Wisteria frutescens) or Kentucky wisteria (Wisteria macrostachya), which are excellent alternatives to the Asian species.
Do you want to know how to distinguish between North American and Asian species?
While North American wisteria is not quite as aggressive in its growing tendencies and has smooth seed pods and fruits in addition to more-or-less cylindrical, bean-shaped seeds, Asian wisteria is an aggressive grower with fuzzy seed pods. Another difference is that American and Kentucky wisteria’s flowers appear after the plant has leafed out in the late spring, whereas the Chinese wisteria’s blooms appear before its foliage.
When to Plant Wisteria
- Plant during the plant’s dormant season in the spring or fall.
- Wisteria can be grown from seed, although plants from seeds frequently take many years to mature and begin to bloom. It is advised to buy wisteria plants that are already established or to begin with a cutting.
Where to Plant Wisteria
- Put a plant in full sun. Even while wisteria will grow in some shade, it won’t likely bloom. Sunlight is necessary.
- Wisteria should be grown in fertile, wet, but well-draining soil.
- Wisteria will grow in most soils unless it is in bad condition, in which case you need add compost. Find out more about soil improvements and getting the soil ready for planting.
- Because wisteria grows swiftly and can easily engulf its neighbors, pick a location apart from other plants.
- Additionally, wisteria is renowned for encroaching on and infiltrating surrounding buildings like homes, garages, sheds, and so on. We highly advise against growing wisteria too near your house!
- Wisteria vines need a very strong support, like a metal or wooden trellis or pergola, to climb on. Plan carefully and use substantial materials to construct your structure because mature plants have been known to become so heavy that they destroy their supports.
Wisteria looks gorgeous growing up the side of a house, but use caution when planting it because it is a very strong vine that will get into any crack or gap!
Caring for Wisteria
- Apply a 2-inch layer of mulch and a layer of compost under the plant each spring to keep moisture in and keep weeds at bay.
- Phosphorus is often used by gardeners to promote flowering. In the spring, work a few cups of bone meal into the soil. Then, in the fall, add some rock phosphate. Study up on soil amendments.
- If you get less than an inch of rain each week, water your plants. (To determine how much rain you are receiving, set an empty food can outside and use a measuring stick to gauge the depth of the water.)
- During the summer, try pruning the out-of-control shoots every two weeks for more blooms.
Pruning Wisteria
- In the late winter, prune wisteria. Remove at least half of the growth from the previous year, leaving only a few buds on each stem.
- Also prune in the summer after customary flowering if you prefer a more formal appearance. On fresh growth, spurs from the main shoots of the wisteria develop its blossoms. Trim back every new shoot from this year to a spur, leaving no more than 6 inches of growth. So that there are no free, trailing shoots, the entire plant can be trained, roped in, and otherwise organized throughout this procedure.
- Mature plants that have been cultivated informally require little to no more pruning. However, for a plant that has been formally trained, side branches should be pruned back in the summer to 6 inches, then again in the winter to 3 buds.
- Possess you a fresh wisteria? After planting, aggressively prune the vine. Then, the next year, trim the main stem or stems to a height of 3 feet from the growth of the previous year. After the framework has grown to its full size, midsummer extension growth should be cut back to where it started that season.
Wisteria is it indigenous to America?
Stunning hanging bunches of purple blooms are produced by the woody vine known as American wisteria. North America is the species’ natural habitat. It is a suitable replacement for the Chinese and Japanese wisterias, which have spread invasively in some regions.
Wisteria is either Chinese or Japanese.
Wisteria usually grows around historic homes. Chinese wisteria and Japanese wisteria are the two wisteria species that have escaped into the eastern United States. When wisteria becomes established, it can be challenging to get rid of it and can cling to trees and plants in the area for years. In the landscape, they can kill or alter desirable trees.
Vegetative Growth
There are some recognizable vegetative differences between Chinese and Japanese wisterias. Japanese wisteria twines clockwise, whilst Chinese wisteria twines the opposite direction. Japanese wisteria leaves typically have 11 leaflets, but Chinese wisteria leaves can have up to 713 leaflets. Positive identification, however, can be challenging due to some overlap in leaflet traits and the existence of hybrids (Wisteria x formosa Rehd.).
Pinnately complex leaves are typically alternately placed on the stems of wisterias. Leaflets are typically 14 inches long and elliptic to ovate in form. Chinese and Japanese wisterias are high-climbing vines that can grow up to 70 to 80 feet in height, but American wisteria [Wisteriafrutescens (L.) Poir.] only reaches 1525 feet. In Sierra Madre, California, a Chinese wisteria set a record by having a stem length of more than 450 feet. Chinese and Japanese wisterias are typically only constrained by the structure they are supported by. Wisteria stems (vines) tightly wrap around living supports like trees, gradually killing them. The bark on the stems is light brown or tan and relatively smooth. There are produced both lateral and vertical stems. Rooting along the length of the plant, lateral stems normally get more tense with age. Either stem type’s removal can be challenging.
Flowering and Seeds
Before the leaves appear, the Chinese and Japanese wisterias blossom in the spring. Hanging clusters of fragrant flowers with white, violet, or purple petals are produced. A densely hairy (velvety pubescent) legume (seedpod) that has one to four seeds develops from flowers.
Dispersal
Wisteria spreads sexually by seed or vegetatively through stem growth. Since the fruit is deadly, wildlife does not likely spread it frequently. Most likely, infestations in most regions of the United States were made possible by intentional planting as an ornamental for landscape purposes.
Habitat
Fence rows, woodlands, and other landscape features may be affected by wisterias. The surrounding vegetation is replaced by the dense thickets that wisteria develops. These thickets may provide as a habitat for some animals, but they are a formidable barrier to both animal and human activities.
Distribution
Although there are allegedly many Chinese and Japanese wisterias in the eastern United States, the presence of fertile hybrids may jeopardize the current species range. In the United States, American wisteria can be found from Massachusetts to Michigan and south to Florida and Texas. All are cultivated, especially Chinese and Japanese wisterias and their hybrids. The Midsouth is covered in wisteria. American wisteria grows in and around marshes and is typically less aggressive.
Chemical
Since there aren’t many labeled advice for controlling wisteria, more research is required. For suggested chemical applications, see Table 1. These herbicides can be used as foliar, frill, basal bark, cut stump, or soil treatments, among other ways of application. With frill, sometimes known as hack and squirt, an incision in the bark must be made every 2 inches all the way around the woody stem. The herbicide is then sprayed into these apertures. The lower 1824 inches of the entire plant trunk are sprayed with a bark-penetrating adjuvant to apply basal bark treatments. When applied right before bud break, these treatments are most effective on trunks with a diameter of less than 4 inches. After cutting the main stem, applications are performed to the cut stump. To stop the remaining stump from resprouting, spray herbicide on it slightly inside the bark. A nonionic surfactant must also be used in all foliar and basal bark applications at a rate of 3264 ounces per 100 gallons of spray solution. Applications done within two times the dripline of attractive trees may result in harm or death because picloram is absorbed by tree roots. Several desirable trees can be sprayed with clopyralid, making it an excellent option for treating wisteria-draped trees.
Mechanical
Although mechanical controls are an option, they are frequently pricy and labor-intensive. Climbing stems create lateral stems (vines) at their base, which can spread far from the original plant. Climbing vines can encircle trees and shrubs in a tight web that makes removal challenging. Young branches can be pruned by snapping them, but older vines must be clipped.
Is wisteria a natural plant?
Wisteria blooms over roads and arbors in the spring, reminding me that sure, spring always keeps its promise and, wow, this stuff is taking over the globe! Although some varieties of wisteria are stunning, they are invasive plants and should be grown with caution (if at all).
The native American species is a perfect substitute if you adore the rich splendor of wisteria because it provides you all the glory without nearly as much trouble.
Chinese and Japanese Wisteria
Wisteria sinensis and Wisteria floribunda, respectively known as Chinese and Japanese wisterias, are magnificent spring-blooming vines with gracefully twisted trunks and an absolutely gorgeous display of pendulous lavender or pink blooms in the spring. These are the varieties of wisteria that grow wild along highways and drape their foot-long flowers from tall tree branches.
They are very stunning. However, when these non-native vines are accidentally introduced into American forests (often by well-intentioned gardeners), they quickly proliferate and start the troublesome work of obstructing light and water, growing thickets, impeding the growth of new saplings, and even bringing down large trees with their heavy, woody stems.
Despite being invasive species, Chinese and Japanese wisterias are still sellable, and it can be tempting to take a cutting or sprout from a naturalized vine. But before putting wisteria into your yard, you might want to consider how diligently you intend to train and control it.
American Wisteria Is the Native Choice
Consider growing the less invasive American wisteria as an alternative (Wisteria frutescens). This gorgeous vine, which is native to eastern North America, is just as magnificent despite having slightly smaller blooms that occasionally repeat in the fall. It is significantly less intrusive and much less likely to spiral out of control than its Asian counterparts.
The blossoms are the most straightforward way to recognize American wisteria. The flowers of American wisteria are shorter, rounder, and more compact than those of Asian species, which have elongated blossoms with loose, dripping petals (rather pinecone shaped). Despite having less fragrant blossoms than Asian wisteria, American wisteria still has stunning flowers! The smooth seed pods of American wisteria can also be distinguished from the hairy seed pots of Chinese and Japanese varieties.
Don’t be deceived when planting American wisteria by the claim that it is “non-invasive”
The tenacious American wisteria swiftly covers arbors and reaches impressive heights in the trees. In comparison to Asian wisteria, it also grows more quickly and is more resistant to cold. Native to marshes in the southeast, American wisteria thrives in some sunlight.
Wisteria Fact
Did you know that the wisteria vines of various varieties entangle in various directions? While American and Japanese varieties climb clockwise, Chinese wisteria twines counterclockwise.
How to Grow American Wisteria
When cultivating American wisteria in your yard, remember to:
- Water: Wisteria might require a little irrigation during dry seasons because it is a native of marshes.
- Use a trellis: Instead of letting wisteria climb trees, train it to a trellis or arbor to keep it under control.
- Gently Tie: Since wisterias twine to climb (rather than cling), it may be necessary to gently tie them to the trellis until they round it.
- Keep Pruning: If a vine is not taken care of, it could grow out of control. Maintain wisteria in its intended location and cut back any sprouts or tendrils that stray onto nearby bushes or trees.
Wisteria: a problem species?
Background In 1916, Chinese wisteria was first made available as an ornamental plant. Despite being weedy and disruptive, it has been widely planted, grown, and is still highly popular in the nursery industry.
Availability and Habitat Chinese wisteria, which is widely distributed in the eastern United States, has been found to be invasive in at least 19 states, ranging from Massachusetts to Texas south to Illinois. Although established vines will survive and propagate in moderate shade, wisteria likes full sun. Vines cling to trees, bushes, and man-made objects. Although it can tolerate a wide range of soil types and moisture levels, it likes deep, loamy soils with good drainage. Common locations for infestations include the edges of forests, the sides of highways, ditches, and right-of-ways.
Ecological Danger The tough, woody vines firmly entwine themselves around the trunks and branches of the host trees and sever the bark, causing death by girdling. On the ground, new vines that grow from seeds or rootstocks produce thickets that smother and shade out native plants and obstruct the growth of natural plant communities. Canopy gaps that result from dying girdled trees allow more light to reach the forest floor. While this might momentarily benefit certain local species, it also encourages wisteria to grow and spread vigorously.
- Plant: a clockwise-climbing, deciduous, woody twining vine with strong, smooth, gray-brown stems that are dusted with tiny white hairs. The diameter of older plants can reach 15 inches or more.
- The leaves are complex, alternating, and have 9–11–7–13 leaflets that are egg-shaped with wavy borders and sharply tapering points.
- Flowers, fruits, and seeds: Prior to the development of leaves, flowering takes place in April. The flowers are lavender to purple, appear in pendulous racemes or clusters 6-8 (up to 12) in long, and mostly open at once. Individual flowers are 0.8-0.9 in. long on 0.6-0.8 in. long stalks (pedicels). The fruits are green to brown velvety seedpods 4-6 in. long, narrowed toward the base with constrictions between the 1-3 flat,
- Spreads vegetatively by creating stolons, which are above-ground stems that develop shoots and roots at irregular intervals, as well as via seed, which in riparian environments can be transported by water.
- Look-alikes include the Japanese and American wisterias (Wisteria frutescens), which have leaves that are 7 to 12 inches long, 9 to 15 leaflets that are all the same size, plane margins, tips that are acute to slightly tapering, smooth bright green above, and slightly milky undersides. They bloom in May after the leaves have expanded, with flower clusters that are 4-6 inches long and not particularly pendulous, and individual flowers that are about 3/4 inches long and
Control and Prevention Cut vines to free trees from the weight and girdling caused by modest infestations. Use a systemic pesticide containing glyphosate or triclopyr on the lower cut stem sections. From a seed, new plants may sprout. Long-term planning is necessary (see Control Options).