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.
How can I speed up the growth of my wisteria?
Growing conditions and time are key considerations when it comes to the fast sprawl we so independently desire to see for our Wisteria. Wisteria can grow swiftly in the ideal area, but it won’t grow at all in unfavorable ones. We’ve listed our top 10 suggestions for wisteria growth below.
Tip 1: Give It Time
It’s typical for newly planted Wisteria to not grow for the first year or two. Wisteria often grows quickly, but it also lives a long time and requires time to establish itself.
If the wisteria was planted within the last two years and hasn’t yet flourished, it might just be establishing its root system. Give it another year, and there’s a strong chance that next summer it’ll start growing like crazy, so as long as the foliage is healthy, don’t panic. Wisteria occasionally takes up to five years to begin the renown quick development you read about, but it rarely does.
Tip 2: Treat Any Pests or Diseases
If your wisteria has pests or a disease, that can be preventing it from growing. A sickly wisteria may have wilted patches, yellow or brown leaves, and blotches on the leaves or stems. Examine the plant thoroughly for pests.
Scale insects, borers, aphids, honey mildew, powdery mildew, leaf spots, and crown rot can all affect wisteria. Clearing up any health issues your wisteria may have may be necessary to get it to start growing again.
Tip 3: Make Sure It Gets Plenty of Sun
The full sun is good for wisteria, especially when it is young. Older plants and some Wisteria kinds can survive partial shade, but if your plant isn’t growing, it may not be getting enough sun.
When your wisteria is already planted in the ground, this can be difficult to correct. If nearby plants are shading the wisteria, think about trimming or moving them. (If getting your Wisteria additional sun isn’t possible, you might just want to buy another one and plant it in a brighter place.) Although Wisteria doesn’t always respond well to being moved, you can also try transplanting.
Tip 4: Water
Wisteria is thirsty, especially when it is mature. Lack of water may be the cause of your wisteria’s appearance of wilting if the weather has been dry. Give it some water, but watch out not to drown it, especially if your soil doesn’t drain well. Wet feet bother Wisteria.
Tip 5: Improve Your Soil
Although wisteria isn’t very particular about its soil, it does have some demands, and the improper soil could limit its ability to develop normally. The ideal soil for growing wisteria is deep, moist, neutral to mildly acidic, neutral to mildly fertile, and well-drained.
You might try adding some compost to the soil surrounding the wisteria if your soil doesn’t drain well. Additionally, try to prevent compacting the soil by walking on it as little as possible. When you must go there, lay down mulch to help support your weight.
Apply some ferrous, ammonium, or garden sulfur to your soil if it is alkaline (the polar opposite of acidic). Through your local extension office, you can have your soil tested.
Tip 6: Fertilize (or Stop Fertilizing)
Although Wisteria doesn’t require exceptionally fertile soil, if your soil is seriously lacking in nutrients, you may need to add fertilizer to help your plant develop. This is especially true if you’ve neglected to fertilize or repotted your Wisteria plant in a few years and it’s growing in a container.
Wisteria can convert and use atmospheric nitrogen, making it nitrogen-fixing like other legumes, so it typically doesn’t require a nitrogen fertilizer. You might use an all-purpose fertilizer instead because young plants can benefit from a little extra nitrogen, which promotes foliage growth. Since bone meal mostly offers phosphorous, many gardeners use it to feed their Wisteria.
Funny thing about fertilizer is that using too much or too little can both be hazardous. If your wisteria has been receiving fertilizer but isn’t growing, consider stopping the fertilizer application and giving the soil a nice flush with lots of water. Your soil may get overly fertilized, which could harm your plants.
The subject of fertilizing wisteria is covered in its entirety in another article. Locate it here.
Tip 7: Prune
Wisteria normally needs to be pruned to prevent it from becoming too big, but a good trimming can also spur growth. Pruning promotes branching rather than a few shoots growing very long. Additionally, if you see suckers, which are little starts at the base of the plant, trimming those can encourage the wisteria to direct its energy elsewhere.
Tip 8: Give It Something to Climb
It likes to climb trellises, arbors, fences, walls, and trees. Wisteria is a twining vine. Give your wisteria something to climb up so it can get taller. If you want your Wisteria to climb on something, just make sure it’s robust and that you don’t mind it getting fully covered in vines after a few years. Learn more about teaching Wisteria to climb here.
Tip 9: Twine It In the Right Direction
Make sure you are twining your Wisteria in the correct direction if you are training it to grow around something. Chinese and American wisterias twine counterclockwise, whereas Japanese wisteria twists clockwise. Your wisteria won’t be able to develop properly if you twist it in the wrong direction.
Tip 10: Plant It In the Ground
Your wisteria might not have enough room or nutrients to thrive if it’s in a container. For wisteria to achieve that voracious growth, it needs to bury its roots deeply into the soil. Although wisteria can be grown effectively in pots, a small container may provide a challenge.
A regular nutrient replenishment is also more crucial for container soil than for garden soil. Every year, you must feed container soil with compost or fertilizer.
Make sure to use optimal techniques if you decide to move a Wisteria from a container to the garden. Wisteria is occasionally unresponsive and challenging to transplant.
What can I do to aid wisteria?
Wisteria weighs a lot. When it is very old, its main stems may be as thick as a small tree trunk and reach a thickness of several inches. When you plant, keep the future in mind; otherwise, your wisteria will end up with a vine that is too heavy for its support.
Wisteria is typically grown on strong arbors or pergolas, up walls, or both. Start by attaching a number of 6- to 8-inch L-brackets to the support in order to secure it against a home wall. One row of brackets runs vertically up the middle of the wall at 1-foot intervals, and the other rows run horizontally at 2- to 3-foot intervals. To prevent vines from encroaching on the eaves, fasten the top row 3 feet below the eaves.
Galvanized wire should be run between the brackets. After that, attach the baby wisteria vine with string; as it grows, its stems will twine around the wire. (There is plenty of area for air circulation and growth because the wire is placed 6 to 8 inches away from the wall.)
Make sure that the support posts of the construction are at least 4 by 4 inches in size if you want to plant wisteria up an arbor or pergola. Keep the main stem firmly tied with heavy-duty garden twine until it has grown over the top of the building and is attached there. The main stem can be twined around a post or grown straight against it.
Leave the lateral branches on the main stem while the wisteria is growing, especially in the first year or two. After the plant has established healthy growth, you can start gently pinching or trimming off lateral growth at the plant’s base. As the vine climbs the post and moves along the arbor or pergola ceiling, keep trimming some of the lateral growth each year.
When the vine reaches the roof, tie it in place and direct its growth horizontally. It will be held in place as it ages by its own weight and the twining side branches. If you wish to continue lashing it down for more protection, make sure the ties aren’t girdling the branches once a year.
What ought I give my wisteria to eat?
Feed wisteria plants each spring for the best results. A rose or flowering shrub feed will typically yield better results, while Miracle-Gro Growmore Garden Plant Food and Miracle-Gro Fish, Blood & Bone All Purpose Plant Food are both options. Feed plants in very well-drained soil with sulphate of potash in the summer as well.
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.