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.
Which month is ideal for wisteria planting?
The best seasons to plant wisteria are spring or fall, and you should put it in full sunlight to ensure that you get to view its lovely blossoms. A wet, well-draining soil is ideal for wisteria.
Is it necessary to put wisteria in the ground?
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:
Where should you not plant wisteria?
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.
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You can keep your wisteria vines looking excellent by following these growing guidelines.
Where space permits and gardeners are dedicated to keeping them in check, wisteria are tenacious, twining vines that are used widely in landscapes. They possess endurance, vitality, longevity, and the capacity to scale great heights. They are highly prized for their springtime huge, pendulous flower clusters. Pea-like flowers come in a variety of colors, including white, pink, lilac blue, bluish purple, and purple. The fruit, a long, flattened, green pod, is not particularly attractive. The plant has alternate, pinnately complex leaves and climbs on twining stems. An inch-plus-diameter twisted, woody trunk is not uncommon in older, more established plants.
Wisteria needs full sun (six or more hours of direct sunlight per day) and a deep, somewhat fertile, moist soil that does not dry out too much in order to blossom successfully. Although they can adapt to most soil types, they perform best in neutral to slightly acidic soils with a pH of 6.0 to 7.0. Since mature plants can be fairly heavy, some sort of support will be required.
Plant establishment will be ensured by thorough site preparation. To find out whether the soil’s pH or phosphorus level has to be corrected, perform a soil test first. If so, as you are preparing the soil, add more components. In an area that is two to three feet in diameter and 18 to 24 inches deep, prepare the soil. To enhance soil aeration and drainage, mix one-third by volume of peat moss, compost, or well-rotted manure into the native soil.
On wires, trellises, arbors, and pergolas, wisterias grow best. If the right supports are present, such as rows of wire anchored four to six inches from the wall, they can be grown on solid, vertical surfaces. Use strong, long-lasting materials like wood, tubing, or galvanized wire. Since they don’t rust, copper or aluminum wire or tubing is chosen over other metals. For pergolas and arbors, pressure-treated wood should be used. However, avoid planting wisteria where the stems can encroach on building gutters and obstruct them. Wisteria can also be cultivated as a tree-form or a single trunk standard. The plant needs to be staked upright in order to do this. Its top is severed when it reaches a height of four to five feet. On the top of the stem, side branches are allowed to grow, but the lower stem is regularly pruned. Each winter, side branches are clipped to a length of six to eight inches until the top reaches the appropriate size. Future pruning is removing secondary branches that form immediately after the first or second leaf and trimming summer shoots as soon as they reach their sixth or seventh leaf. These secondary shoots are pruned back in the winter to just an inch from their base. The use of living trees as support is common, but it must be done cautiously. By girdling the stem of the twining wisteria, trees with a diameter of less than ten inches can be quickly killed. Damage to larger trees is also possible. To prevent girdling, trees that are used should be monitored periodically. The previous girdling stem must be physically removed from the tree to prevent further damage if a tree is being girdled; however, the wisteria can be cut back to the soil line and allowed to grow again.
The vine can be planted once the soil has been prepared and the support structure is in place. Put the plant’s root ball in the hole so that it doesn’t go any deeper than where it grew in the nursery. Set your grafted wisteria so the graft union is just below the soil’s surface if it is. The prepared soil mixture should be poured into the hole and compacted around the root ball. After planting, thoroughly wet the area. An inch of water per week, provided either through irrigation or rainfall, is needed for new plants. Young plants should receive annual fertilization until they occupy the designated space. Young vines won’t likely bloom because vegetative growth is being promoted. If the branch and foliage development and color are healthy and the plant has filled the designated space, do not fertilize. Only water if the foliage starts to wilt, which could happen during a drought. Both of these methods reduce floral production while promoting vegetative growth.
To maintain plant quality, some annual pruning is necessary; it is not recommended to let the vine grow haphazardly and take over neighboring plants and buildings. Pruning will encourage flowering and help the vine become less vigorous.
Choose a strong, upright stem to act as the primary leader and attach it to the support to train plants on a wire trellis or an arbor. other side sprouts, remove them. As the primary leader expands, it will form side branches that will later generate additional shoots and flower buds. To create a framework that fits the designated space, keep training the main leader upward and the new side branches as necessary (allow about 18 inches between side branches). When the main leader reaches the desired height, pinch it off.