When To Grow Wisteria

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 distinction is that the flowers of American and Kentucky wisterias appear in the late spring after the plant has begun to leaf out, whereas those of Chinese wisteria do not.

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.

Which month is ideal for wisteria planting?

The best seasons to plant wisteria are spring or fall, and you should put it in full sunlight to ensure that you get to view its lovely blossoms. A wet, well-draining soil is ideal for wisteria.

When should wisteria be done?

If wisteria seedlings have at least two sets of leaves or are 4 to 5 inches (10-13 cm) tall, experts advise planting them outside in the spring or summer. Additionally, you must make sure there are 45 days before the first anticipated frost in your area before planting.

Your seedlings should be planted in a spot that receives full sun for at least six hours each day. You should put your seedlings close to a wall, trellis, or fence and make sure the soil is well-draining.

Give your wisteria plant enough space to spread out and climb since it is a fast-growing vine that can grow 10 feet (3 meters) or more in a year.

Again, cuttings will result in blooming wisteria plants much more quickly, and the new plants will reproduce the qualities of the parent plant if you’re not willing to wait up to fifteen or more years for blossoms.

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.

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 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 long does a wisteria take to flower?

The issue may be improper fertilization, which may be the solution. In the spring, fertilizing can promote leaf growth while discouraging blooming.

The problem can also be a lack of maturity. If your wisteria was grown from seed or was given to you by a friend, it may not yet be old enough to flower. However, most wisteria purchased from plant nurseries is ready to bloom. Wisteria cannot blossom until they are between the ages of 7 and 15.

Overpruning is the last and least likely cause of a wisteria’s failure to bloom. The flower buds will be removed by overpruning. However, it is quite challenging to overprune a wisteria.

Wisteria can endure the winter.

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.

Can wisteria survive a cold climate?

Wisteria vines can withstand a wide range of environmental factors, but the majority of types struggle in zones below USDA 4 to 5. Wisteria plants in Zone 3 were a bit of a pipe dream because these beloved plants of temperate climates often died during the cold, prolonged winters. Zones 3 to 9 are favorable for Kentucky wisteria, a chance hybrid that can be found in the swampy regions of south central United States from Louisiana and Texas north to Kentucky, Illinois, Missouri, and Oklahoma. In the cooler location, it even consistently produces flowers.

Japanese and Chinese wisteria are the two varieties grown most frequently. Chinese wisteria is appropriate down to zone 5, whereas Japanese wisteria is a little more hardy and thrives in zone 4. The Kentucky wisteria is descended from the American wisteria, Wisteria frutescens.

The plants naturally grow in highland thickets, riverbanks, and marshy woodlands. While Kentucky wisteria may flourish as low as zone 3, American wisteria is hardy only to zone 5. Wisteria can be grown well in zone 3 thanks to a number of novel cultivars that have been released. Compared to its Asian counterparts, Kentucky wisteria is less pushy and more well-mannered. Even after severe winters, it regularly blooms in the spring with slightly smaller flowers.

In USDA zone 3, Wisteria macrostachya, another plant, has also demonstrated its dependability. It is marketed under the name “Summer Cascade.”

The best wisteria vines for zone 3 are Kentucky wisteria plants. Even a few cultivars are available for selection.

A Minnesotan cultivar named “Blue Moon” sports tiny, fragrant clusters of periwinkle blue flowers. In June, vines can reach lengths of 15 to 25 feet and bear racemes of fragrant, pea-like blooms that are 6 to 12 inches long. These zone 3 wisteria bushes then develop 4–5 inch long, velvety, soft pods. The plant’s delicate, pinnate, dark green leaves on twining stalks only add to its allure.

The aforementioned “Summer Cascade” has racemes of delicate lavender blooms that are 10 to 12 inches long. Other varieties include “Clara Mack,” which has white blooms, and “Aunt Dee,” which has lovely antique lilac flowers.