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.
Where should a wisteria plant be planted?
According to Kirsten Coffen, a landscape architect and designer based in Maryland, “its gorgeous spring-blooming cascade of purple (or white) scented flowers is best observed when trained on a structure, such as a robust pergola.”
Such a lush, floral canopy offers delightful shade throughout the sweltering summer months. According to Irene Kalina-Jones, a landscape designer at Outside Space NYC (opens in new tab), “We plant it on rooftops in the city, training it to cover pergolas to create shade.” “But I enjoy it grown against buildings, too,” you say.
Wisteria grows best in full sun in a protected location, such as a south or west-facing facade. When planting, work in a lot of organic matter (such as compost) to ensure that the soil is rich and well-drained.
If you want to grow wisteria up a wall or the front of a house, put some effort into building a strong structure that it can climb over many years. A tensioning system of wires is possibly preferable to a wooden trellis because wood can rot. The wires must either automatically tighten as the plant gains weight or be simple for you to tighten (via turnbuckles, for instance).
Is wisteria able to become a shrub?
With its velvety foliage and big, drooping clusters of fragrant flowers, wisteria is one of the few plants that may give elegance and romance to the landscape. Wisteria is basically a strong deciduous vine, but it can be coaxed to grow into a tree or shrub.
Wisteria can be planted right now. Although most wisteria plants are still dormant, they should begin to sprout soon and flower in April or May. Jim Kitano, the manager of Kitano Garden Center in La Palma, claims that some mature vines continue to bloom well into the summer.
There are roughly ten different species of wisteria, however this region is most frequently home to the Chinese native Wisteria sinensis.
‘Alba,’ a variety of Chinese wisteria, has white flower clusters that can reach 2 feet in height; ‘Caroline,’ with dark purple-blue blooms; and ‘Cooke’s Special,’ with deep purple blooms. Because of its lengthy blooming period, which begins in spring and lasts into summer, the latter type is more well-liked.
The following advice will help you successfully grow this striking vine:
* Grow plants in full sun in a location that receives at least six hours of daily direct sunshine.
* When growing as a vine, pick a location where the plant can spread out because wisteria vines can grow endlessly and can reach heights of up to 120 feet. An arbor, patio roof, fence, or other solid structure is what the vine will need to grow on.
* Purchase one that has been trained in this way, or prune and train it, to develop as a tree or shrub. To achieve this, cut all stems apart from the main stem and stake it with horticultural tape made of plastic.
Pinch the plant to force branching at the height you want the main branches to appear from, and remove any buds that sprout below that height by rubbing them off.
* Offer effective drainage. Although wisteria is not picky about the soil, it cannot stand having wet feet. Fill a 2-foot-deep hole with water until it stops draining to check the area’s drainage. It ought to have entirely emptied by the time you come back 24 hours later. Select a spot with better drainage if there is standing water.
Dig down 2 1/2 feet and amend with one-third planter’s mix to loosen up hard clay before planting.
When wisteria starts to grow, water it once or twice a week when it doesn’t rain. In warm weather, established plants older than three years need a good soak once a week.
* Three times a year, fertilize. Use a nitrogen-rich fertilizer, like a 16-16-16, in the spring and summer to stimulate general development. Use a fertilizer with more phosphate and potassium in the fall, such as 5-20-10. This will promote healthy flowering and deep roots.
* Pick a pot with a minimum 20-gallon capacity if you want to grow wisteria in a container. Depending on the weather, use a high-quality potting soil and water your plants every three to five days. Feed outside plants similarly to indoor ones.
* Prune wisteria after a year of development after the plant’s late spring or early summer flowering period is over. Trim to regulate shape and size.