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.
Does wisteria harm the ground beneath it?
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.
Types of wisteria:
There are two varieties of wisteria: Asian and American. Although aggressive growers, Asian wisterias are well-known for their stunning blossoms. American wisterias are less aggressive and still produce beautiful blossoms. Compare the most popular wisteria varieties.
Flower color:
Wisteria comes in a range of colors, such as white, pink, and blue tones, in addition to the well-known purple blossoms. If you believe you have seen a yellow wisteria flower, it was probably a golden chain tree (Laburnum).
Foliage:
Wisterias are deciduous, which means that when the weather becomes chilly in the fall, they lose their leaves. The misunderstanding is occasionally brought on by a different vine known as evergreen wisteria (Millettia reticulata).
Avoid planting aggressive wisterias close to your home as they can cause damage and have even been known to destroy buildings.
Wisterias can be grown in full sun or partial shade, but to promote healthy bloom development, make sure the vines get at least six hours of direct sunlight everyday. If you reside in a colder area, pick a planting location that is protected because a heavy spring frost can harm the flower buds.
Create a planting hole that is the same depth as the plant and twice as wide, then level the plant with the soil surface. Because the vines will soon fill in, you should space your plants at least 10 to 15 feet apart along the support structure.
Wisterias don’t need much care once they are planted to promote healthy growth. Water frequently over the first year until the roots take hold.
After planting, wisterias could take some time to come out of dormancy and might not start to leaf until early summer. They will leaf out at the regular time the following spring, but don’t be surprised if they don’t bloom. Wisterias take three to five years to reach full maturity and may not start blooming until then.
Wisterias grow quickly and can reach heights of up to 10 feet in in one growing season. That works out well if you need to quickly cover a fence or pergola but don’t want the vines to take over your landscape. Regular pruning (once in the summer and once in the winter) not only controls wisteria’s growth but also encourages more robust flowering by creating a framework of horizontal branches and causing spurs to grow at regular intervals.
Cut back the current year’s growth to five or six leaves in July or August, or roughly two months after the plant flowers, to get rid of stray shoots and make short branches that will produce flowers the following year. Summer pruning needs to be done more frequently. Re-prune the plant in January or February while it is dormant by removing two or three buds from the growth from the previous year.
The first few years of wisteria’s growth are crucial for creating the desired framework for the plant’s development. As soon as your wisteria begins to grow, start connecting particular lateral shoots to its support structure. You should also cut down any extra growth. An aggressive pruning may be required on elder plants to promote the growth of new branches. Cut down aging branches to the main primary stem to accomplish this. The spaces will soon be filled with new side branches that can be connected back into the support structure.
Visit the Royal Horticultural Society to view a video on how to prune wisteria vines properly.
Do I need to grow wisteria on my house?
Wisteria can be grown against a house wall or another robust building, like a sturdy pergola. Wisteria can be grown in a container, but only if done so as a conventional tree and with regular trimming to keep its shape. This is a highly labor-intensive option.
How to plant wisteria
Wisteria can be planted in spring or fall. Plant at the same level as it was in the original pot and water in thoroughly after thoroughly preparing the soil to guarantee a proper root run. Like an espalier fruit tree, tie the stems to horizontal galvanized wires connected to the wall. Remove all but one stem if it is climbing a pergola, and tie this stem to the post.
How to plant wisteria in a pot
Wisterias can be planted in pots, but because they are hungry plants, you will need to feed them frequently. Choose this option only if you’re training your wisteria to be a standard. Use a quality tree and shrub compost and the biggest pot you can fit. Plant at the same height as it was in the first pot and give it plenty of water.
How to care for wisteria
The wisteria plant is ravenous. During the growing season, fertilize once a month with a high potash fertilizer to promote greater flower blooming. Weekly wisteria fertilizer and watering. Use organic mulch in the fall, such as well-rotted horse dung or homemade compost, to protect your plants.
How and when to prune wisteria
Wisteria should be pruned twice a year in August and February. Focus on integrating the plant into the support throughout the first few years. This entails cutting back side shoots to five buds in early August, training in strong side shoots, and removing very low branches.
How to prune wisteria in summer
Wisteria that is pruned in the summer will produce short spurs that will transport the spring blossoms.
- Cut the long, robust shoots back from the base of the current season’s growth to a few buds.
- Choose a few sturdy shoots from young plants (less than three years old) to tie to wires or a trellis.
- Simply cut back side shoots on older wisterias to the base of your strong shoots.
Expert David Hurrion demonstrates how to prune wisteria in the summer in this little video. He demonstrates which stems to cut and how much to remove precisely:
How to prune wisteria in winter
By pruning both in winter and in the summer, you can promote the growth of the short spurs that bear the spring blooms. Anytime between late October and March is the dormant season, so do this.
- Connect fresh growth to the main structure to increase its support
- Cut back the remaining long stems sharply.
David Hurrion demonstrates how to control robust, leafy growth so it doesn’t cover budding flower buds in this video on winter-pruning wisteria:
How to propagate wisteria
Few gardeners cultivate wisteria; most opt to purchase a plant instead because it can take up to 20 years for a wisteria to bloom from a cutting. However, take softwood cuttings in the middle of April if you’re up for a battle.
- Young stems should be cut into lengths and trimmed to 10 cm, just below a leaf joint.
- Leave roughly four leaves at the top of each cutting after removing the lower ones.
- Fill pots with cutting compost, then fill them with water and let the water drain.
- Cover the cuttings with a clear plastic bag after inserting them into the pots so the leaves don’t contact.
- Make sure the cuttings are kept moist by keeping them in a well-lit area.
- Remove the bag and pot after growth is visible.
Growing wisteria: problem solving
Lack of blossoms is the most frequent issue wisteria gardeners encounter. Expecting blooms before the plant is four years old may be impractical because wisterias take their time to bloom.
David Hurrion provides tips on where to plant your wisteria, how to prune it, and how to feed it to get the most blossoms here.
Will wisteria damage my foundations?
In the spring, a house covered in wisteria looks magnificent. Can the roots harm your foundations, though? In our Quick Tips video, Catherine Mansley from BBC Gardeners’ World Magazine explains:
How can you defend wisteria from the house?
I usually move quickly past my wisteria with little fear, and occasionally when I speak to it, I tell it, “You are a plant. The human is me. I am in command. But until I came out with a flawless method to control it, neither the wisteria nor I really believed it to be the case.
Not getting wisteria to grow is the difficult part
It enjoys poor soil, direct sunlight, and the side of your house, but there are ways to teach it to grow well next to the house. Wisteria needs the assistance of a sturdy trellis system for that.
Wisteria tendrils will wrap themselves around any available supports in either a clockwise or counterclockwise direction. I used substantial stainless steel components to build a grid system at my home so that the wisteria could thrive.
The grid’s components include affordable hardware purchases (you can also buy them online from Sears). I spent $1.99 per 3.75-inch-long stainless steel Lag Eye Bolt (Top), $62 for a 125-foot spool of stainless steel cable, and $24.05 for a box of ten stainless steel turnbuckles.
Once your trellis is set up, you may train it to grow next to the grid by tying individual branches to the cable. Pruning wisteria ferociously will keep it in check. Trim side shoots along major branches to a length of 3 inches in the fall and winter.