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 flower on both old and fresh growth?
In the preceding growing season, Wisteria generates its flower buds (“blooms on old wood”). Those buds were taken out if the plants were clipped from late fall to early spring. There are several actions you may take to nudge a wisteria toward blooming.
Is there a second bloom on wisteria?
Your wisteria plant will often only produce one bloom from early spring to late summer. A second bloom has, however, occasionally been successful for some persons in the late summer or early fall. Of course, you won’t get as many blooms as in the first bloom, but you might be able to lengthen the bloom season and enjoy the spectacle for a little while longer.
Deadhead spent blooms as soon as they begin to wilt or droop if you wish to get a second bloom. Even while there is no assurance that you will receive additional bouquets, it might be worth you to try. Visit this post for all the information you need to know about when and how to deadhead your wisteria.
Your best strategy is to try to keep your plant as healthy as possible and in ideal conditions as the environment and growing conditions both play a significant part in whether or not your wisteria is likely to produce more blooms.
How old must a wisteria be before it blooms?
The issue may be improper fertilization, which may be the solution. In the spring, fertilizing can promote leaf growth while discouraging blooming.
The problem can also be a lack of maturity. If your wisteria was grown from seed or was given to you by a friend, it may not yet be old enough to flower. However, most wisteria purchased from plant nurseries is ready to bloom. Wisteria cannot blossom until they are between the ages of 7 and 15.
Overpruning is the last and least likely cause of a wisteria’s failure to bloom. The flower buds will be removed by overpruning. However, it is quite challenging to overprune a wisteria.
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.
Should I remove the wisteria’s dead flowers?
Wisteria pruning is relatively simple, but it’s necessary if you don’t want it to spread beyond its designated area each year.
This can happen whenever the plant is dormant, from the moment the leaves have dropped to the conclusion of the winter.
- It’s crucial to just eliminate new growth to promote flowering because flowers grow on the growth from the previous year.
- Trim lateral branches in the winter, leaving only one or two buds.
This is to leave the main branch alone and to prune all of the stems that grow from it.
- Because the fruits of wilted flowers are poisonous, remove them frequently (deadheading).
What can I give my wisteria to encourage blooming?
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.
Is a lot of water required by wisteria?
The most important factor to consider when growing wisteria is location. Since wisteria is a twining vine, it needs a strong support and regular pruning to stay in check. Wisteria thrives in open locations with easily manicured lawns surrounding them.
Although it will withstand a variety of soil types, this vine needs deep, rich soil that is slightly damp.
About the only significant requirement for wisteria vine maintenance after planting is pruning. Wisteria doesn’t need fertilizer because it grows quickly and is drought-tolerant, so it just needs a little water.
What do wisteria’s bloom buds resemble?
With a distinct basic structure, wisteria thrives. Consider this to be the “armature” or structural base from which blossoming growth develops.
The fundamentals are the same, with a few minor variations, regardless of whether it has been espaliered, trained as a standard (a free-standing tree form), along a porch, over an arbor, or in any other shape. Although it is simpler to train a young plant, the guidelines apply to even the oldest wisteria vines.
For the purposes of this essay, I’ll suppose that our fictitious wisteria is planted against a wall, but same guidelines apply to any other growing situation.
Where to make cuttings can be determined by inferring a vine’s structure and seeing where it flowers and where it doesn’t.
Primary leader: The primary leader is the plant’s primary vertical component. In more mature plants, the main leader frequently splits into multiple leaders.
Any branch that emerges from the main stem is a side shoot. To reduce congestion, some side shoots will be chosen to become laterals, while others should be cut out as needed.
Secondary branches, also known as laterals, are side shoots that develop from the leader and are joined together to form the plant’s sturdy secondary branches.
Side shoots that develop from tertiary laterals. A few of these become blooming spurs (short side shoots where flower buds typically develop).
It’s also critical to understand the various bud shapes. In contrast to leaf buds, which are narrower and more pointed, flower buds are rounder and larger. The larger buds in the image below are flower buds, while the smaller, more angular buds are leaf buds.
What can I do to make my wisteria bloom twice?
A spectacular, opulent vine known as wisteria will enchant you with its heavenly blossoms year after year. However, the profusion of flowers that cover a pergola, wall, or arbor isn’t always simple to achieve. You’re not the only one who is interested in learning how to encourage your wisteria vine to produce more flowers.
You should concentrate on the surroundings and general health of the plant if you want to encourage your wisteria to blossom and generate more blooms. Make sure it receives the appropriate amount of water, sunlight, and nitrogen from the soil. Correct Wisteria pruning can also promote more blooms.
When should a wisteria be pruned?
Twice a year, in January or February and again in July or August, wisteria is pruned. When this fast-growing climber is pruned in the summer, the long, whippy tendrils are trimmed back to five or six leaves.
The goal is to both limit the wisteria’s growth—which has a propensity to go out of control and hide behind gutters and downpipes or into roof spaces—and to direct the plant’s energy into flowering rather than leafy development.
How do I prune wisteria in winter?
The plant’s energy is further focused on developing flower-bearing spurs as a result of the pruning that is done now, in January or February. You will find that pruning is lot easier than it sounds because the plant is dormant and without leaves, which makes it simple to see what you are doing.
At this time of year, all that has to be done is to work over the climber and prune the same growths even more, this time down to two or three buds.
When you’re done, you’ll have a climber covered in stubby little spurs that are all covered in buds that will bloom in the late spring. The blossoms won’t be hidden by a tangle of leafy branches thanks to this severe pruning.
If branches are blocking doors or windows or there is old or dead vegetation on older plants, more drastic pruning may be required. Always prune just above a robust young shoot lower down and trim stems down to a major branch with the goal of leaving a frame of stems that are evenly spaced apart and cover the required area. If required, tie in more stems to close gaps.
Wisteria sinensis ‘Prolific’ is a good choice as a starter plant if you don’t already have a wisteria and want one. Try Burncoose Nurseries or Peter Beales, both of which have a large selection.