In large canopy trees, the woody vine known as wisteria can reach heights of 70 feet (20 meters).
Bark
The diameter of the vine stems can reach 10 inches (25 cm). Alternate branching occurs. Chinese wisteria’s older bark is compact and dark gray with light-colored lenticles (dots). The bark of Japanese wisteria is white.
Leaves
With 7 to 13 leaflets for Chinese wisteria and 13 to 19 leaflets for Japanese wisteria, the leaves are alternate, odd-pinnately compound, and 4 to 16 inches (10-40 cm) long. The leaflets range in shape from oval to elliptic, measuring 1.6 to 3 inches (4–8 cm) long by 1 to 1.4 inches (2.5–3.5 cm) wide. Initially fairly hairy, mature leaflets become mainly to entirely smooth. The petioles are quite short, and the edges of the leaflets are smooth and wavy.
Flowers
On the Chinese species, dense, pendulous clusters of 6 to 12 inches (15-30 cm) long pinkish purple to blue-lavender, pea-like blooms hang from the stems and open almost simultaneously. The blossoms of Japanese wisteria open one by one from the base to the tip of the inflorescence, which is 8 to 20 inches (20–50 cm) long. In April or May, flowering typically takes place as the leaves are extending. Both types, but especially Japanese wisteria, have strong fragrances.
Fruit
Fruit is a flattened, 1.5 to 6 inch (38 to 150 millimeter) long, tapering to the base, and constricted between the seeds legume pod. Greenish brown to golden, velvety hairy pods split apart to release the seeds. 0.5 to 1 inch (1.2-2.5 cm) in diameter, flat, spherical, brown seeds that ripen from July to November.
How is wisteria grown in Tennessee?
Wisterias from China and Japan are well-liked ornamental plants, and for each species, there are a number of named cultivars. They can create thickets that are so dense that little else can grow because they are aggressive and hardy. By girdling or over-topping the stems of trees, they kill them. The Fabaceae (Pea or Bean) family includes wisteria.
A perennial vine called wisteria has a lifespan of up to 50 years. The main method of growth is vegetative reproduction; multiple stolons produce new roots and shoots at regular intervals. If the vines are covered with leaf litter, it will root at the nodes. If the conditions are right, wisteria can also generate a lot of seeds, although flower buds that are developed in the fall are vulnerable to winter mortality. In riparian settings, seeds may travel enormous distances in water as they are carried downstream. Animal distribution is hindered by large seed size.
Habitat
Wisteria thrives in full light, although older vines can tolerate some shade and continue to grow. They frequently climb the nearby foliage to reach the sun. By suffocating the stems or shadowing the crown, twining wisteria vines can lessen the vigor of rival plants. The wisteria favors loamy, deep, and well-drained soil, while it can endure a range of soil types and moisture regimes from wet to dry. Although populations are frequently found along woodland borders, roadsides, ditches, and rights-of-way, they frequently expand from neglected gardens.
Origin and Distribution
Around 1830, Japanese wisteria was brought to Europe as a decorative. It was widely used as an ornamental accent in gardens, gazebos, porches, and walls in the southern United States. Chinese wisteria originated in China and was first made popular in 1916. Wisteria can be found in New England and a few other places further north because it is a hardy plant.
Where does wisteria grow?
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.
Wisteria trees can endure the winter.
Wisteria (Wisteria spp.) plants have long pendants of fragrant purple or white flowers that dangle in a weeping manner. They are a favorite flower for climbing over arbors, training up a wall, or growing as a conventional tree. When grown, wisteria can readily withstand harsh winters and flourishes in U.S. Department of Agriculture plant hardiness zones 4 through 9. However, young wisteria plants might not be able to withstand the first winter after planting without some protection from frost and chilly winds.
In the fall, water the wisteria plant frequently to maintain moist but not soggy soil. The plants may move nutrients from the soil and store them for the winter by receiving regular watering in the fall. When freezing conditions are predicted, water plants liberally to prevent desiccation of the leaves when the temperatures cause the moisture inside to freeze, leaving frost on the leaves.
To protect the vine’s roots from the cold throughout the winter, cover the base with a 4-inch layer of organic mulch. Anything from crushed bark mulch to dried leaves can be used. To ensure the entire root ball is insulated, keep the mulch a few inches away from the vine and cover a space that is at least 2 feet in diameter.
Wrap the main stem of the wisteria plant with a section of thin-walled plastic tubing. With a razor knife, cut the tubing lengthwise, then pry it open to allow it to fit around the wisteria stem. The plastic tubing is less expensive than using frost cloth or leftover fabric, which are typically far larger than what is required for the stem.
Create a temporary walled enclosure to safeguard the plant. Using a reciprocating saw, extend four 2-by-2-inch wooden posts by about 24 inches beyond the height of the wisteria. Using a hammer, pound the four stakes about 18 inches into the ground. Place the stakes evenly spaced around the plant, 18 inches from the stem.
Frost cloth, burlap, or another type of fabric can be used to cover the stakes. Without letting air escape around the plant’s base, the cloth must be big enough to completely cover the structure. If you require more than one piece of cloth, make sure the ends are at least six inches apart. Set up some bricks or rocks on the ground to hold the extra length in place. The inside temperature of the building stays higher than the outside temperature thanks to the heat that is radiated from the ground surrounding the plant and is trapped by the frost cloth or fabric.
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.
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.
Canines are wisteria poisonous?
Because wisteria doesn’t have a bad taste, dogs may eat deadly amounts of it.
Wisterias are absolutely gorgeous, with cascades of flowing purple blossoms. However, their leaves and blooms can also be dangerous in excessive numbers, and their seeds (and seed pods) are extremely poisonous to dogs.
Even worse, the results take time to manifest. Wisteria also doesn’t taste unpleasant, making it simple for dogs to consume excessive amounts before you realize there is a problem.
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.
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).
In Zone 5, how do you cultivate wisteria?
This is not a difficult plant to cultivate if you have plenty of sunlight, space, and a strong support. It prefers good drainage and a slightly alkaline soil and is hardy to zone 5. When it is in bloom, it requires a lot of water and does best in an area protected from severe winds. As legumes fix their own nitrogen and adding more will diminish flowering, avoid feeding them with high-nitrogen fertilizer.