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.
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.
Wisteria: a perennial plant?
Despite its forceful character, many gardeners adore the magnificent wisteria vine, which is covered with clusters of fragrant blossoms throughout the spring. This perennial, which has a very aggressive growth habit, can quickly get out of control if not carefully controlled. Here are some suggestions for cultivating wisteria’s best qualities while controlling its unruly growth patterns.
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.
How long does a wisteria live?
A perennial vine known as wisteria bears gorgeously scented blossoms, frequently lavender, that develop in clusters resembling grapes.
However, the wisteria that is widespread in the Southeast is actually an invasive species from China. Chinese wisteria spreads so quickly that it eventually engulfs neighboring plants, shades them out, and even kills trees.
Due to its unchecked growth and capacity to flourish in a variety of environments, Chinese wisteria (Wisteria sinensis) has the propensity to harm regional ecosystems. While Chinese wisteria prefers rich loam and needs sunlight to produce its distinctive blossoms, it will still thrive in shadow and can survive a variety of soils.
Wisteria has the ability to climb up tall trees and will continue to spread over the tree canopy, shading out nearby smaller trees and plants. Additionally, wisteria plants can live for more than 50 years. This longevity only boosts wisteria’s capacity to spread and suffocate local plant life.
What should wisteria be used for in the winter?
Winter pruning: After the summer pruning, long, whippy shoots that grew should also be cut back. Cut these back from the main branch to five or six buds, right above a bud. Winter pruning: Cut summer-pruned shoots even shorter in January or February.
After a freeze, will wisteria reemerge?
Wisteria usually survives freezing conditions, although blooms, buds, and leaves might not. Your plant may emerge from dormancy and begin producing new growth if you experience a severe frost or freeze, particularly if it occurs later than usual or after a warm time. This growth will be lost for a while if it is frozen.
As long as the main vines don’t freeze or become black, the plant should be fine. By lightly scraping the bark with your fingernail, you can always determine if there is life there. The plant is still alive if there is some green showing underneath. If a portion of the vine is completely brown, it cannot be revived because it is dead.
Your vine might not start producing buds or blooms again for several weeks, months, or even the entire following growth season after a freeze. Wisteria can be picky when it comes to flowering, so any additional strain on the plant could affect the process.
After a freeze, if your wisteria seems brown and dry, you should wait a few weeks before trimming it. The plants occasionally return on their own without any help. Chopping away growth when it’s unnecessary can lead to cutting away this year’s buds. Long-term damage to the plant wouldn’t result from doing this, but nobody wants to forfeit their flowers.