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.
Is American wisteria shade-tolerant?
Wisteria frutescens, sometimes known as American wisteria, is a woody deciduous vine that twines counterclockwise and can reach heights of 40 feet or more. It is endemic to the region from Virginia through Illinois south to Florida and Texas, and is generally found in damp thickets, swampy forests, pond margins, and stream banks. It is frequently seen in North Carolina’s coastal plain but hardly ever in the Piedmont. Wisteria sinensis spreads more quickly and aggressively than American wisteria (Chinese wisteria). Wisteria floribunda (Japanese wisteria) twines clockwise, whilst Wisteria frutescens (American wisteria) and Wisteria sinensis (Chinese wisteria) twine both counterclockwise.
It thrives in full sun, soils that are somewhat acidic, humusy, moderately fertile, wet, and well-drained. For the best flowering, full sun is required; it cannot thrive in complete shadow. It can take longer, but the vines might start to bloom in the second or third year after planting. In order to manage the growth and shape of the plant and promote flowering, vines require regular pruning. For details on the initial training of vines and the kinds of pruning that can or should be done for these plants, see a pruning guide. The best time to perform any severe pruning is in the spring, right after blossoming. Early spring fertilizer applications might also encourage flowering. Because plants detest being transferred, choose your growing locations carefully. It is well known that the plant can fix nitrogen in the soil. When measured in years, seed-based propagation is extremely slow, whereas shoots and cuttings grow much more quickly.
Plant pests, diseases, or other issues:
susceptible to a multitude of insects that feed on foliage, the honey fungus, and other fungi that cause illnesses. Many factors, including wintertime frost damage to flower buds, excessive shade, immature plants (particularly those developed from seed), poor pruning, and overfertilization, might prevent vines from flowering.
Does wisteria require shelter or the sun?
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.
Which wisteria does shade best?
Although the majority of wisteria plants like full sun, a shaded location is occasionally the only choice. If it applies to your garden, it doesn’t mean you can’t take advantage of one of these lovely plants. Wisteria sinensis is the ideal wisteria for shade. One of the few Wisteria cultivars with a potential for partial sun blooming is this one.
But remember that most Wisteria require full sun to bloom. You may never get to witness the magnificent sight of the plant completely bloomed if you choose to plant yours in partial sun or shade.
Can wisteria thrive in dim conditions?
Mandarin wisteria (Wisteria sinensis) The American cultivar has the drawback of not flowering in the shade. On the other hand, Chinese wisteria blooms exquisitely in the shadow, but gardeners take a chance dealing with its possible invasiveness.
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.
Can wisteria grow on a wall that faces north?
For growing this most magnificent of horticultural spectacles, Alan Titchmarsh offers tips.
There are several benefits to spring arriving slowly. After a bitterly cold, rainy, and snowy winter, when army-blanket skies were the norm week after week and month after month, it is disheartening to have to wait so long for flowery joys.
Late springs, on the other hand, lessen the possibility of early development, which can frequently be severely scorched by late frosts. Due to unanticipated freezing conditions at the end of the month, a friend’s wisteria, which had put on a stunning annual display for fifty years, was dripping with depressing, grey flower trails in April last year.
Given that the buds didn’t even begin to open until the middle of April, they had high expectations for the kind of show that has become synonymous with their home this year.
How much I adore wisteria! When we got married, it graced the front wall of our humble three-up, three-down terrace house. I trained it with pride so that, during the six years we lived there, its territory grew year after year.
It was the common Chinese wisteria (W. sinensis), which for a long time was the only kind to grow in our gardens. Numerous cultivars with weird names and, in certain cases, strange colors and flower forms are available today, the majority of which are of Japanese origin.
At the Kawachi Fujien Wisteria Garden in Kitakyushu, Fukuoka, Japan, a wisteria tunnel is in full bloom.
If you’re planting a new one, make sure you like the color and blossom shape before purchasing a grafted plant because it will bloom more consistently and much earlier. A few inches above soil level, the graft union will be readily evident. There are strategies to induce blooming in older reticent plants, including those that weren’t grafted and were reproduced by layering or cuttings.
You need a sunny wall for wisteria. Giving it a wall with a north or east facing side is a waste of time. The most favored directions, where the wood will ripen most efficiently, are south and west. The pruning process itself is done twice a year. All questing growths that are required to increase the plant’s coverage should be tied in by July; all others should be cut back to around 1 foot. All sideshoots should be pruned to finger length in January. If you repeat this each year, your plant shouldn’t let you down.
Gorgeous Lodge House in Smeeth, Kent, close to Ashford, has a Georgian front covered in thick wisteria.
Wisteria is a twiner and doesn’t have sticky pads like Virginia creeper or aerial roots like ivy, so your wall will need some sort of support system. The least noticeable support is provided by strong horizontal wires attached to strong vine eyes screwed into the wall at intervals of 18in.
The likelihood of this happening can be reduced by regularly untangling the stems during winter trimming. A well-attached trellis can be used, but the snaking branches can get behind it and, as they fatten over the years, they can rip it from the wall.
Every March, you may encourage regular bloom and strong development by giving your wisteria a liberal serving of rose fertilizer, which is rich in potassium and magnesium, which assist flowers open up. If your wisteria has been pruned, nourished, and grown on a sunny wall for three or four years and still won’t bloom, consider it a failure, yank it out, and plant a grafted type that will catch up to it.
The wisteria-covered entrance to Dunsborough Park in Ripley, Surrey, is like the doorway to paradise.
The ancient standby Macrobotrys, which has flower trails that may reach a maximum length of two feet, is my personal favorite of the several types that are offered. The elegant white variety are just as striking as the lavender purple ones in the correct circumstances.
The plain W. sinensis, whose flower trails emit the most scrumptious aroma in spring sunshine, is a plant I would never avoid, especially if it were planted near a bedroom window that could be opened to let in the intoxicating scent.
Being so demanding with food and water, wisteria plants are difficult to grow successfully in pots and other containers. You can grow wisteria as a free-standing “standard” on a 5 foot bare stem if you don’t have access to a suitable home wall. It will require some support, but when I was a student at Kew Gardens, I recall enormous free-standing specimens there that were already well over a century old. They scuttled around a rusting iron structure that they had all but destroyed like boa constrictors.
To enjoy the pleasures of late spring and early summer in the company of one of the most stunning members of the plant world, all we need right now is the kind of sunny weather that was lacking earlier in the year.