Which Wisteria Is Not Invasive

If you want to add floral vines to your yard, choose a nursery that can suggest non-invasive plants to protect your landscaping and the environment. The EDIS publication “Flowering Vines for Florida,” which offers images, details on growth conditions, and flowering dates on a number of flowering vines suitable for Florida settings, is another excellent resource.

The “Amethyst Falls” In the teaching gardens at the Gulf Coast Research and Education Center, American Wisteria (Wisteria frutescens ‘Amethyst Falls’) is growing.

Wisteria frutescens, also known as American wisteria, and millettia reticulata, also known as evergreen wisteria, are both gorgeous, non-invasive alternatives for your home’s landscape. The vivid blue/purple blossoms of the native American wisteria cultivar “Amethyst Falls” bloom in the spring and summer. The blossoms won’t require the frequent pruning and vigilance associated with Chinese or Japanese wisterias, even though they might not be quite as fragrant.

A plus is that American wisteria serves as a host plant for the larvae of both the long-tailed skipper and silver-spotted skipper butterflies. Only USDA zones 5 to 9 are suitable for American wisteria, therefore it won’t thrive everywhere in Florida.

Fortunately, the fragrant flowering vine evergreen wisteria, also known as summer wisteria, can take the place of invasive wisteria in gardens around the state. A non-native, non-invasive vine with small, fragrant flowers that bloom in the summer, evergreen wisteria has glossy, leathery green leaves. Evergreen wisteria, which isn’t really a wisteria, can grow in USDA plant hardiness zones 8 to 10, preferring full sun, though it can also tolerate some shade.

Both of these vines are better suited for cultivation in your home landscaping because they are more fragile and grow less quickly than invasive wisteria.

Wisteria vines: are they invasive?

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).

What distinguishes wisteria from China and Japan?

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 grown, notably hybrids of Chinese and Japanese wisterias. 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.

What makes wisteria invasive, exactly?

Nonnative invasive species of southern forests: a field guide for identification and control, James H. Miller, 2003. SRS62, General Technical Rep. Asheville, NC: Southern Research Station, U.S. Department of Agriculture, Forest Service, 93 p.

Plant: up to 70 feet (20 meters) long deciduous high climbing, twining, or trailing leguminous woody vines (or cultivated as bushes). Due to probable hybridization, it is challenging to identify between Chinese and Japanese wisteria.

Stem. Woody vines with sporadic alternate branching and a diameter of 10 inches (25 cm). Twigs with short, thick hair. Compared to Japanese wisteria’s white bark, the older Chinese wisteria’s bark is tight and dark gray with light spots (lenticels).

Leaves. With 7 to 13 leaflets (Chinese) or 13 to 19 leaflets (Japanese) and stalks with swelling bases, these alternate, unusual pinnately complex plants range in size from 4 to 16 inches (10 to 40 cm). Oval to elliptic leaflets with tapering, pointy ends 1 to 1.4 inches (2.5 to 3.5 cm) width and 1.6 to 3 inches (4 to 8 cm) length. At adulthood, the hair ranges from being completely hairless to being short and smooth. entire and wavy margins. short petioled or sessile.

Flowers. April to May. When leaves first appear, dangling and spectacular stalked clusters (racemes) measuring 4 to 20 inches (10 to 50 cm) long and 3 to 3.5 inches (7 to 9 cm) wide appear.

9 cm) across. Chinese flowering all around the same time, or gradually from the base (Japanese). Pea-like flowers with purple to violet corollas (to pink to white). Fragrant.

seeds and fruit. June to November. Flattened legume pod, 0.8 to 1.2 inches (2 to 3 cm) broad, 2.5 to 6 inches (6 to 15 cm) long, and irregularly oblong to oblanceolate. One to eight flat, round, brown seeds, each measuring 0.5 to 1 inch (1.2 to 2.5 cm) in diameter, are released when the velvety hairy, greenish brown to golden, fruit splits on two sides.

Ecology. Where plants were once planted, create extensive infestations. occur in damp to dry environments. Colonize by runners roots at nodes while vines are coated in leaf litter, as well as by vines twining and covering shrubs and trees. Along riparian zones, seeds are distributed by water. Large seeds are less likely to be dispersed by animals.

W. frutescens (L.) Poir., which resembles native or naturalized American wisteria and does not produce significant infestations, grows in moist forests, blooms in June to August after leaves have emerged, and has slender old vines, 6-inch (15-cm) flower clusters, 9 to 15 leaflets, and hairless pods. Additionally, Campsis radicans (L.) Seem. ex Bureau, which has leaflets with coarsely toothed margins, may resemble trumpet creeper.

usage and history. introduced in the early 1800s from Asia. traditional porch vines in the South.

Recommendation for control measures:

Wet all leaves completely (till runoff) with one of the herbicides listed below in water with a surfactant:

  • every year from July to October, when regrowth begins Tordon 101* at 3% (12 ounces per 3-gallon mixture), Tordon K* at 2% (8 ounces per 3-gallon mixture), or Garlon 4 at 4% (15 ounces per 3-gallon mix)
  • every year from July to September, when regrowth starts to appear
  • To protect nearby vegetation, use Transline* as a 0.5 percent solution in water (2 ounces per 3-gallon mixture).
  • repeated applications of a 2-percent glyphosate pesticide from September to October (8 ounces per 3-gallon mix)

* Root uptake may cause harm or death to non-target plants. Transline has limited power over different plant species. Rainfall must occur within six days of the application of Tordon herbicides in order to activate the soil. Herbicides made with tordon are restricted use pesticides.

Are the roots of wisteria trees invasive?

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.

How can invasive wisteria be managed?

So how can you get rid of wisteria after it has grown too much? Wisteria removal might be difficult, but there are various methods you can try. Start by manually picking or digging up any sproutlings. To stop the wisteria from resprouting, cut it to the ground. All wisteria branches (and seed pods) should be bagged up and disposed of to prevent the possibility of new sprouts appearing elsewhere. Then, for permanent wisteria eradication, apply a properly formulated herbicide, such as a non-selective kind.

To the stump, paint or immediately apply the pesticide. You might wish to re-treat them if more sprouts appear in the future. Spraying the foliage should only be done as a last option to protect surrounding plants.

Before cutting and removing the wisteria vine, some people instead opt to soak the leaves or as much of the vine’s tip as possible in a herbicide solution for around 48 hours. Although the majority of herbicides are intended to target certain plants without damaging other vegetation, you should still exercise caution when using them.

For the correct application, please follow the instructions. The optimum time to apply herbicides to eradicate wisteria is in the late summer or early fall. But removing wisteria is probably simplest in the cold.

You shouldn’t encounter too many issues as long as you know how to prune wisteria on a regular basis to keep it under control. Cutting it down and soaking what’s left in an appropriate herbicide may be your only option if your wisteria has grown out of control or if you simply don’t want it.

Recall that organic methods of control are more environmentally friendly and should only be employed as a last option.