Very rarely do we find wisteria vines that aren’t spectacular and enchanting. Whether they are hanging on a pergola or an archway or climbing up the side of a house, when the wisteria blooms, it’s a glorious sight and fragrance to behold. The blue, white, or purple flowers of the wisteria signal the entrance of spring. Depending on which zone you are in or country, you can enjoy the view as early as March or May.
This twining climber can grow to epic proportions and can live through centuries. The largest known wisteria is recorded on the Guinness Book of World Records as the largest blossoming plant in the world. It’s a Chinese Wisteria that was planted in 1894 in Sierra Madre, California by the couple William and Alice Brugman. The vine currently weighs more than 250 tons and is more than one acre in size. There’s an annual Wisteria Festival in the Sierra Madre if you want to join in on the celebration of that beauty.
Meanwhile, in Asia, Japan may be most popular for its cherry blossoms, but it also boasts of one of the oldest wisteria vines located in Ashikaga Flower Park. This tree dates back to 1870. This living history will tell us that planting wisteria isn’t just planting for our consumption, but for generations to come. With proper care and maintenance, your children’s children will enjoy your floral legacy.
But first, caution.
Even as we fawn and watch in awe of the wisteria vine, it remains our duty to give you this word of warning: plant wisteria with caution. Whatever variety the wisteria may be, whether it’s the Japanese Wisteria, Chinese Wisteria, American Wisteria, or their sub cultivars, this vine is dangerous and poisonous. All parts of the plant contain toxins called lectin and wisterin glycoside. Ingesting any part of the plant can cause nausea, diarrhea, vomiting, and in severe cases, confusion. While it is rarely fatal, animals and humans who might consume large amounts of the wisteria’s seed beans can die of poison.
Interestingly, wisteria belongs in the pea family (Fabaceae), along with the sweet pea vines. After spring when the flowers have faded, the vine produces seedpods. These long seedpods ripen and turn brown and “pop”. If you’ve ever heard wisteria make loud popping noises, it’s the explosion caused by the seedpod, ejecting seeds as far away from the parent plant. It’s an ingenious design by Mother Nature that ensures that wisteria vine can grow and grow without competition. But again, these pods are poisonous too. Beware!
It’s also worth noting that several U.S. states have classified wisteria as an invasive species. The Wisteria floribunda (Japanese) and Wisteria Sinensis (Chinese) are not native to North America. The great alternatives if you’re planting to grow these blooms in your garden is to choose the species that are native to the U.S., some of which are the Wisteria frutescens (American) and Wisteria Macrostachya (Kentucky). We will delve deeper into these varieties below.
In This Article
Planting Wisteria Vines
When To Plant
The best time to plant wisteria is when it is dormant, during the spring or fall season. If you are up to the challenge of growing wisteria from seed, understand that it will take a few years before you see any flowers bloom. Maybe you can plant one at the birth of one of your children to make it even more special. But if you want to enjoy the wisteria flowers sooner rather than later, we recommend buying an established wisteria plant or start from a cutting.
How to Plant Wisteria
If you’ve made up your mind, and your area allows for growing the gorgeous wisteria vines, it’s time to start planting! Very simply, you have to dig up a hole as deep as the root ball, and about 2 to 3 times as wide. Ensure that the hole is deep enough to cover the roots, but it must not cover the plant’s crown. If you end up covering the crown, this will lead to root rot and your wisteria will not survive. “Wet feet” is the worst enemy for wisteria vines, because they enjoy well-draining, loose, and loamy soil. The soil quality must have adequate aeration and plenty of nutrients. Add compost if you have poor soil. The right soil amendments and soil preparation will ensure the best growth and blooms for the plant.
The ideal spacing for wisteria plants is at least 10 to 15-feet apart to give space for each of your wisteria plants to grow.
Choose a site in your garden that receives full sun throughout the day. Wisteria may flourish in light situations of partial shade, but if you want to enjoy her full blooms and maximum growth, bright direct sunlight is essential.
Wisteria tends to overtake her neighbor plants, so we advise that you plant it away from others. Note that the wisteria vine is known for growing onto nearby structures. They are powerful vines and can grow into houses, sheds, garages, and other structures. To allow the vine to grow to its fullest potential, give it something to climb on. A strong metal trellis or pergola is ideal. With this plant, think of the long-term – mature wisteria vines can get so heavy that they might break a weak structure.
Wisteria Vine Varieties
Many US states consider this wisteria variety an invasive vine. You may not want to add this to a landscape with other plants. This is the kind of plant you want to be growing on its own. It will take time to mature, but it can live up to 100 years. And once it blooms, with clusters of bluish and purple flowers drooping from its branches, the beauty will be worthwhile.
Botanical Name: Wisteria Sinensis
Other varieties of the wisteria vine require full sun, but the Chinese wisteria can tolerate some level of shade. However, it may not blooms as robustly or frequently as you’d like. There are several methods to try if you want the flowers to bloom. Applying fertilizer with high phosphorus content can promote blooming.
A moderately fertile and humusy soil is ideal for the Chinese Wisteria. They prefer a slightly acidic t.0-7.0 soil pH. Your soil must have good drainage. From day one, you have to ensure your location’s soil quality because these vines dislike being moved around.
When your wisteria vine is still young, make it a point to water it frequently and deeply so that it can establish a strong root system. But you must avoid having it sit in wet and soggy soil. Once it has developed, keep a regular watering schedule.
Temperature and Humidity
The wisteria Sinensis can withstand cold temperatures but not prolonged cold, flowers may not bloom as often in this situation. Generally, the wisteria vines prefer high humidity, but they can grow in dry environments provided that there is moisture in the soil.
Pruning and Training
With proper pruning, this type of wisteria vines can form a gorgeous shade canopy overhead. But that’s where the challenge is, also. The pruning and training for this plant can be on the high maintenance side. Again, this is an invasive species, and without regular pruning, their runners will quickly overwhelm their surroundings.
Cut back during the late winter season to remove a year’s growth of vines. Leave just a bit of bud on each of their stems. You may also prune it after the blooms of spring or early summer. Don’t worry if you cut too much off of the plant, they often sprout back up again.
To train the Chinese Wisteria, choose a stem that is growing upright and attach it to your support (pergola or what structure have you). To achieve that upward growth, remove any side shoots that appear. Eventually, one day, you will enjoy your purple burst of shade.
Another variety of wisteria that emits a fragrant smell and delightful flowers is the Japanese wisteria. Like the Chinese Wisteria, the Wisteria Floribunda is also an invasive vine. While the blue to lavender flowers are a sight to behold, this is also a toxic plant that onlookers should be careful about. We recommend removing the seedpods after the plant has flowered, especially if you have pets or children.
Botanical Name: Wisteria Floribunda
One of the reasons you should create a sturdy structure like an arbor or pergola for the wisteria is that it needs full sunlight. Allowing them to climb on a wall or house cast a shadow that isn’t healthy for the plants and your structure. With a pergola, they get full sun exposure, which is considered six hours of sunlight a day.
Be careful not to plant wisteria on very acidic or alkaline soils, they won’t be able to tolerate these conditions. The ideal for the Japanese Wisteria is well-draining and moist soil.
In terms of fertilizing, these trees require less. If you must fertilize, stick to low nitrogen fertilizer. Note that a lack of flowering vines might mean that you are over-fertilizing. You can stop fertilizing and stop pruning the root to shock the plant into flowering.
Until you have mature plants, you should be following a regular watering habit. Once they are strong and established, you can leave the floribunda for infrequent deep watering. Rain showers will do for them and you keep the soil moist especially during the dry seasons.
Temperature and Humidity
With USDA Zones 4-9, the Japanese Wisteria can handle a bit of cold, but it is also sensitive to too much heat. We can’t emphasize this enough: wisteria thrives in moisture.
Pruning and Training
Remember that the Japanese Wisteria will bloom on new growth, on new wood. That means you will constantly need to prune, especially after the wisteria has flowered. This would be in July or during winter. To enjoy the beauty, keep the branches as close to the main structure as possible.
The third wisteria variety that deserves your attention is the American Wisteria. What sets this wisteria apart from the other kinds is that is it non-invasive and less aggressive for your garden. So you can still enjoy its sweet fragrance and its mesmerizing blue flowering branches without the high risk of damage to your other plants or structures.
Botanical Name: Wisteria Frutescens
While the American wisteria can grow in partial shade, the best condition for her to bloom with those blue flowers is when these trees receive full sun exposure. One of the best reasons American wisteria might be for you is that it can bloom more than once and flowering can stretch from spring into summer. The wisteria frutescens is flood-resistant and deer-resistant, too!
If you find wisteria whose leaves are turning a dull yellow, it’s a terrible sign that the soil it’s planted in is too alkaline. Alkaline soil causes many plants to produce less chlorophyll. That’s a problem! From the start of your wisteria planting journey, ensure that your soil is rich, moist, and well-draining. Acidic to neutral pH levels are ideal for these plants.
Consistent moisture is required for the American Wisteria to thrive. Note that this variety is naturally found and native in areas with lots of water like rivers and swamps. During the summer, and on those long hot days, maintain a watering schedule that will nourish the plant and her roots.
Temperature and Humidity
Since the American wisteria is suitable for hardiness zone 5 to 9, moderate humidity is ideal. Most wisteria varieties cannot withstand zones below USDA 4. Zone 3 is a cold climate that poses a challenge for non-hardy wisteria plants. However, new cultivars are popping up that proves to be extremely hardy for freezing conditions. The Kentucky Wisteria is suitable for zone 3 to 9.
Pruning and Training
Like the rest of her wisteria cousins, the American wisteria needs proper pruning to develop new growth and flower. Prune the vines in the late winter season and trim back new shoots in the summer. This way, you are encouraging thicker blooms.
Now that we’ve learned the three most popular varieties of wisteria plants. Let’s dive into some of the most frequently asked questions surrounding this fragrant flowering vine.
The key is to look at the direction the vines are twining or twisting around your arbor or pergola. Japanese wisteria will always grow in a clockwise direction, while the American and Chinese wisteria turns counterclockwise. You can also check out the seedpods, although be very careful! The Asian varieties have a fuzzy and velvet-like surface, while the native wisteria seed pods are smooth.
Where is the best place to plant a wisteria?
Plant wisteria where there is light and legroom. Avoid planting them near your house or with other plants because they are aggressive and invasive.
How fast does the wisteria vine grow?
Growing wisteria and wanting them to bloom will require all your patience. Think of it as a long-term investment. It will take three to five years after planting for them to begin flowering. The foliage on the other hand is vigorous. They are quick-growing vines.
Is wisteria vine invasive?
Wisteria vines are invasive. If left unchecked and under poor maintenance, they will completely twine around structures. The Chinese and Japanese varieties are reported to be invasive in at least 19 states in the US.
Is Wisteria bad for houses?
Wisterias can form heavy wood stems. They are so strong they can creep through any cracks in the side of your home and push their way into any structure. They can clog your gutters, break windows, damage shutters, and more! It’s strongly advised to plant these powerful beauties away from your home.