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.
- Water your plants if you receive less than one inch of rain each week. (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.
The greatest places for wisteria trees to grow
The greatest way to utilize wisteria’s breathtaking beauty and incredible vitality is to grow it as a little tree, or standard. Long racemes of sweet-smelling May flowers hang down from soft, pruned leaf heads and sway slightly with each breeze. The compact head of a Tree Wisteria looks amazing in a mixed bed of perennials, bulbs, and annuals. The impression is beautiful and dignified.
Please be aware that wisterias typically take a while to emerge from dormancy after planting. Please be aware that your plant won’t start to leaf out until early summer. It will thereafter leaf out at the usual time in succeeding years (midspring).
Choosing a Location: Wisterias grow and flower most effectively in areas with plenty of sunlight, preferably at least 6 hours every day. They do well in any kind of soil as long as it drains well.
In order to plant your bareroot Wisteria, take off the packing and give the roots a few hours in a bucket of water. Then, dig a hole that is both large enough to permit the roots’ spread and deep enough to allow you to set the crown, or the location where the stem and roots converge, 1 inch below the soil’s surface. Insert the roots into the planting hole and arrange them naturally or like the spokes of a wheel. The roots of many woody plants are brittle, so use additional care when positioning them in the planting hole to prevent breaking them. With one hand holding the crown 1 inch below the soil’s surface, use the other to push soil into the hole while circling the roots to prevent air pockets from forming. Then, using both hands, compact the soil close to the crown. To create a basin, create a rim of earth around the perimeter of the planting hole. This basin is used to collect, hold, and direct water to the roots. Finally, thoroughly immerse the plant.
Please be aware that once bareroot plants are taken out of their packing, they dry up rapidly, especially on a sunny, windy day. Until you are ready to plant, we strongly advise that you keep the roots wrapped in wrapping material.
Staking: To keep their heads aloft in severe gusts, tree wisterias need additional support. After planting, drive the wooden stake that came with your tree 6 to 12 inches deep and 1/2 inch away from the plant’s trunk into the earth. Using the plastic tie tape that came with the tree, affix the trunk to the stake numerous times, spacing them apart by about 8 inches. You’ll need to swap out the original stake for a bigger wooden stake or a sturdy steel pipe as the head and trunk grow bigger. Check the tree every spring and autumn to ensure that the stake is securely in place and that the tie tape used to attach the trunk to the stake is not excessively tight and preventing the trunk from expanding. Plants need to be firmly staked at all times.
Watering and Fertilizing: To hasten wisterias’ establishment in the first year after planting, they require the equivalent of 1 inch of water each week. If the sky doesn’t provide enough moisture, water deeply once a week. Plants that are established only require irrigation during extended dry spells. Wisterias don’t need much, if any, fertilizing because too much fertilizer prevents blossom. Give plants a gentle feeding of 5-10-10 or 5-10-5 at a rate of 3/4 cup per square yard in the early spring each year if your soil is particularly weak or sandy.
Overwintering: For the first few winters after planting, cover the main stem with a piece of plastic tubing in cold-winter conditions like ours here in Litchfield (Zone 5 [-20F]). To encircle the stem, make a straight incision from one end to the other and pry the cut open. (Precut tubing could be available at your nearby garden center.) To stop wind and frost from damaging branches on older specimens, cat’s-cradle bind the branches together using twine to form a web of intertwined strings.
Pruning: Tree Wisterias need to have the long, twining branches they generate in the summer pruned lightly but frequently in order to maintain the globe shape of the head. A couple of weeks prior to the first date of your first frost, they also require one severe pruning in late summer or early fall. Remove all branches that are in the wrong place and reduce the current season’s development to just 5 to 6 huge buds (leaving stubs that are about 6 inches long). This drastic haircut inhibits growth and promotes the transformation of some leaf buds into flower buds. Don’t let pruning errors keep you up at night. Wisterias are highly understanding plants; strong growth the following season will give you another chance.
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.
Where does wisteria grow best?
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.
Can wisteria be grown in the US?
It makes sense to use native plants in the garden. This is so because local plants are better suited to the area and require less specific maintenance. If they do manage to escape domestication, they won’t harm the wild flora either. One such native plant is American wisteria. American wisteria – what is it? It is a sociable neighborhood vine with charming blue flowers that can fit perfectly in your garden.
The southeastern states are home to American wisteria. It mostly grows in damp bottomlands, including swamps, near rivers, and in flood plains. It may grow as a cultivated plant in USDA zones 5 to 9.
The deciduous vine can reach a height of 30 feet (9 m.). The beautiful pinnate leaves on this rambling beauty are separated into 9 to 15 leaflets. The attractive dangling clusters of pea-like blooms, which are occasionally creamy white but more often blue or violet, dangle from the stems. Compared to the Chinese variety, it is a more regulated plant with velvety pods that offer seasonal interest.
Are dogs poisonous to wisteria?
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 can be found in California?
Our new home has a Wisteria bush that has taken over the patio cover since we moved in. It is so disorganized and unsightly when it is dormant, so I want to remove it. I’m trying to come up with a replacement that is a little greener all year round. One that draws butterflies and birds would be a plus. The sun will be shining directly on the dry ground. I appreciate any advice you may give me.
ANSWER:
There is a gorgeous North American native wisteria called Wisteria frutescens that is not nearly as invasive as the Asian wisteria, or Wisteria sinense, which is likely what you have. Unfortunately, that natural wisteria does not flourish in California and only grows as far west as Texas. You will require semi-tropical flora in Riverside County’s westernmost region, close to the Mexican border. We will search for both in our Recommended Species for Southern California because you did not specify whether you wanted a shrub or a vine to cover your patio. Unfortunately, we were unable to locate any native Southern California evergreen vines; hopefully some of the flowering evergreen shrubs we did locate would serve your needs. To learn more about a plant’s behaviors, wildlife draws, and light needs, click the links for that plant.