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?
Chinese wisteria(Wisteria sinensis) and Japanese wisteria(Wisteria floribunda) are not native to North America and are classified invasive plants in several states. The native wisteria species, American wisteria (Wisteria frutescens) and Kentucky wisteria (Wisteria macrostachya), are fantastic alternatives to the Asian variety, so if you’re planning on adding a new wisteria to your garden, we suggest that you go with one of the North American varieties.
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.
Still Dormant
Actually, there are a number of explanations for why wisteria lacks leaves. Most frequently, the weather may be to blame. Trees and other plants, like wisteria, can frequently be expected to postpone leafing out if spring weather is cooler than usual.
How can you tell if your wisteria is simply slow to start (dormant) or is genuinely dying if it has no leaves? First, check the stem’s elasticity. It’s okay if the plant bends readily. Plant stems that are dead will snap and break off. Next, cut off a small piece of bark or scrape a little of it off. Green denotes good health. Unfortunately, if the plant is brown and dried out, it is probably already dead.
Poor Pruning
Occasionally, inadequate trimming techniques can cause leafing out to be delayed. Cutting off any dieback or ugly growth is perfectly acceptable, but doing so at the incorrect time could delay leafing.
However, doing this action in the spring may enable more light and warmth to reach the innermost branches, encouraging regrowth. Lack of light causes plants to develop more slowly and with fewer leaves. Once it does emerge, it will also be paler in color and have lanky growth. Don’t worry too much if pruning has delayed sprouting; it will happen eventually.
Wisteria Age
In the spring, newly planted tree wisteria could take longer to begin to leaf out. Some individuals might observe regrowth right away, while others might not observe any growth until later in the growing season, between June and late July. You merely need to keep the soil moist throughout this time. Be tolerant. The wisteria will start to leaf out once they have established themselves.
Wisteria Variety
The timing of the leaf emergence can also vary depending on the type of wisteria you have. Maybe you’ve noticed that your wisteria is flowering yet the vine has no leaves. Again, the variety is to blame for this. If you see lovely purple blooms before the development of foliage, you most likely have a Chinese wisteria. On wood from the previous year, this kind develops flower buds. As a result, it frequently blooms before the plant actually starts to grow leaves. After the Japanese wisteria plant has developed new leaves, it blooms.
How often does wisteria blossom each year?
Your wisteria plant will often only produce one bloom from early spring to late summer. A second bloom has, however, occasionally been successful for some persons in the late summer or early fall. Of course, you won’t get as many blooms as in the first bloom, but you might be able to lengthen the bloom season and enjoy the spectacle for a little while longer.
Deadhead spent blooms as soon as they begin to wilt or droop if you wish to get a second bloom. Even while there is no assurance that you will receive additional bouquets, it might be worth you to try. Visit this post for all the information you need to know about when and how to deadhead your wisteria.
Your best strategy is to try to keep your plant as healthy as possible and in ideal conditions as the environment and growing conditions both play a significant part in whether or not your wisteria is likely to produce more blooms.
When does wisteria flower?
A twining, deciduous climbing plant with a long flowering season and fragrant blossoms is called wisteria. When in bloom, a wisteria is a wonderful sight with its long, trailing, fragrant blossoms in blue, purple, pink, or white. Wisteria is typically grown on a south-facing wall. Wisteria is a rewarding plant with lovely flowers that bloom between April and June, and occasionally again in August. While wisteria sinensis twines anticlockwise and is the more vigorous of the two, wisteria floribunda (which twines clockwise) originates originated from Japan. In W. senensis, flowers emerge before foliage, whereas in W. floribunda, flowers and foliage emerge simultaneously.
Wisteria requires a lot of room because it grows quickly, reaching heights of up to 9 meters (30 feet). It can’t stand on its own and needs a framework of wires or supports to develop. Prior to planting Wisteria, it is best to build the structure. Wisteria can survive in light shade as well as full sun, though it prefers the former. The drawback of growing wisteria is that it requires a lot of time and effort to flourish. It has the name “red wheelbarrow plant” on it.
Wisteria is a strong climber, so growing it is not difficult; the challenge is getting it to bloom. Correct pruning is a necessary step to get Wisteria to bloom. To guarantee that wisteria blooms consistently every year, it needs to be pruned twice a year (in the summer and the winter). Flowering depends on pruning. Ladders are required for pruning as the wisteria matures and climbs higher up the wall, increasing the amount of upkeep. Wisteria needs a lot of area because it grows quickly and can be clipped to control its size. Although it may seem obvious, wisteria is best planted in the proper location from the beginning. This is because once established, it is difficult to remove because it has very robust, woody roots.
Wisteria is one of the most beautiful climbing plants, but it’s also one of the most time-consuming and challenging to grow and bring to flower. Your Wisteria will bloom if you follow the Sunday Gardener’s tips and video instructions.
Are you reducing wisteria?
Twice a year, in January or February and again in July or August, wisteria is pruned. When this fast-growing climber is pruned in the summer, the long, whippy tendrils are trimmed back to five or six leaves.
The goal is to both limit the wisteria’s growth—which has a propensity to go out of control and hide behind gutters and downpipes or into roof spaces—and to direct the plant’s energy into flowering rather than leafy development.
How do I prune wisteria in winter?
The plant’s energy is further focused on developing flower-bearing spurs as a result of the pruning that is done now, in January or February. You will find that pruning is lot easier than it sounds because the plant is dormant and without leaves, which makes it simple to see what you are doing.
At this time of year, all that has to be done is to work over the climber and prune the same growths even more, this time down to two or three buds.
When you’re done, you’ll have a climber covered in stubby little spurs that are all covered in buds that will bloom in the late spring. The blossoms won’t be hidden by a tangle of leafy branches thanks to this severe pruning.
If branches are blocking doors or windows or there is old or dead vegetation on older plants, more drastic pruning may be required. Always prune just above a robust young shoot lower down and trim stems down to a major branch with the goal of leaving a frame of stems that are evenly spaced apart and cover the required area. If required, tie in more stems to close gaps.
Wisteria sinensis ‘Prolific’ is a good choice as a starter plant if you don’t already have a wisteria and want one. Try Burncoose Nurseries or Peter Beales, both of which have a large selection.
What factors determine when my wisteria will bloom?
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.
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.
How does wisteria fare over the winter?
Wisteria leaves frequently turn yellow, despite the fact that illnesses rarely affect them.
Do not be alarmed if this occurs in the fall; wisteria lose their leaves in the winter.
But if leaves become yellow or lose their color in the summer, chlorosis is likely to be the cause and is brought on by the soil.
- Wisteria struggles in soil that is very chalky, thick, or clay.
- Put some iron sulfate in the ground.