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.
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.
What is the rate of wisteria tree growth?
Nothing compares to the splendor of a wisteria arbor in full bloom, but sadly, many Midwestern gardeners are unable to grow these exquisite vines.
Japanese wisteria (Wisteria floribunda) and Chinese wisteria are the two varieties of wisteria that are most frequently planted in our region ( Wisteria sinensis).
Japanese wisteria is famous for its fragrant violet blooms, which are produced in clusters that range in length from 8 to 20 inches. A cluster’s individual blooms open one at a time, starting at the base.
Chinese wisteria often has clusters that are less than 12 inches long, with slightly larger individual blooms. A cluster of flowers also has a tendency to open at the same time. Chinese wisteria is less fragrant and less resilient than Japanese wisteria. Both species have cultivars that feature white blooms.
Wisteria is an aggressive twining vine that can become highly invasive in some places. Strong support is necessary for the vines to maintain their rapid growth. When wisteria is established in the right setting, it can grow up to 10 feet each year. It functions best in neutral to slightly alkaline, deep, moist, but well-drained soils.
Since the majority of gardeners are attracted to this plant for its flowers, they are very irritated by its infamous propensity to just grow greenery. This irritating issue may be caused by a variety of factors, including the plant’s immaturity, an excess of nitrogen, a deficiency in phosphorus, poor-quality plants, and an excessive amount of shadow.
Before they can start to produce flowers, Asian wisterias need to attain a certain level of maturity. In actuality, it may take the vines up to 15 years or more to bloom.
Those who have had success with wisteria frequently advise root trimming, using superphosphate, severe shoot clipping, and planting in full light. Most importantly, you should begin with high-quality plants that were grown from cuttings of plants that are known to bloom when they are still quite young. Take cuttings of the stem tips in July if you know someone who is prepared to part with a beautiful specimen. Avoid planting seedling vines since it is impossible to predict their flowering habits due to the genetic diversity of seed reproduction.
Wait until late spring or early summer to prune these vines since they develop their blossoms on last year’s wood in mid- to late May. To keep the plant manageable and regenerative, severe pruning back to three or four buds is frequently advised.
A few native species of wisteria are a little more “tame” than their Asian counterparts. These indigenous species attain flowering age earlier than Asian species because they bloom on the growth of the current season. Although they bloom slightly later in the spring, they can rebloom throughout the summer.
The 20–30 foot tall American wisteria (W. frutescens) blooms its flowers in 4-6 inch long, compact clusters. The most popular cultivar, “Amethyst Falls,” has fragrant lavender-blue blooms. Although ‘Nivea’ has longer clusters of white blossoms, it is less aromatic.
Wisteria macrostachys, which grows in Kentucky, produces flower clusters that are 8 to 12 inches long and densely covered with blossoms. Some people believe this to be an American wisteria subspecies. The hardy Minnesota cultivar “Blue Moon” has incredibly fragrant blossoms that start to develop in June and continue throughout the summer. Both ‘Aunt Dee’ and ‘Clara Mack’ have blooms that are a light lavender color.
Is a trellis necessary for wisteria trees?
Flowering vines can be utilized to obscure a view, provide shade for a quiet area, and enhance the aesthetic of a post or arbor in addition to providing color throughout the year.
Due to its aggressive climbing nature, wisteria needs very strong supports in order to develop without bringing down its trellis or pergola. Be careful while growing wisteria near or onto your home since it will grow into any crack or fissure. And keep in mind that wisteria can be quite challenging to get rid of after it has grown.
How far away from your home should wisteria be planted?
The wisteria vine is renowned for its exquisite, scented flowers and its brisk growth. Wisteria can transform an ordinary wall into a flowering waterfall in the spring or an arbor or pergola into something out of a fantasy. However, it needs the correct circumstances in order to flourish and bloom so extravagantly. For optimal benefits, how should Wisteria be planted?
Wisteria needs space to spread out and something to climb, and it should be planted in full sun. Because wisteria needs at least six hours of direct sunlight each day to bloom, plant it facing south or west. Your wisteria plants need at least 15 feet between each other.
The main things to think about when planting Wisteria are the things it will be climbing, how much trimming it will require, and making sure it will get enough sun. If your winters are particularly chilly, it’s also a good idea to pick a sheltered location. Find out where and when to grow wisteria by reading on.