The photos I am about to show you are of Japan’s largest Wisteria plant, also known as Wistaria. It is located in the Ashikaga Flower Park and while it's not the biggest in the world, many people say it is the most impressive.
The size of the 140-year-old plant, which looks more like a tree, is about 1,990 square meters (half an acre) and it is held up by a complex structure of steel supports. Visitors are allowed to walk below and bask in the pink and purple light of the sun as it comes through the canopy. A truly amazing sight I am thankful I got to see.
Wisteria is notable not only for its attractive, fragrant flowers, but also for its vigorous growth. The vine may grow 10 feet or more in one year, and can easily overwhelm nearby plants and structures. Heavy annual pruning is necessary to keep it in bounds. The vines become large and woody with age and need sturdy support. Flower colors include blue, red, lavender, and white, depending on the variety.
Wisteria vines climb by twining their stems either clockwise or counterclockwise round any available support. They can climb as high as 20m above the ground and spread out 10m laterally. The world's largest known Wisteria vine is in Sierra Madre, California, measuring more than 1 acre (0.40 ha) in size and weighing 250 tons. Planted in 1894, it is of the Chinese lavender variety.
Wisteria, especially Wisteria Sinensis, is very hardy and fast-growing. It can grow in fairly poor-quality soils, but prefers fertile, moist, well-drained soil. They thrive in full sun. Wisteria can be propagated via hardwood cutting, softwood cuttings, or seed. However, specimens grown from seed can take decades to bloom; for this reason, gardeners usually grow plants that have been started from rooted cuttings or grafted cultivars known to flower well.
The hidden side of this vine is its amazing vigor and the ability of its tendrils to grow swiftly underground, popping up far away from the main plant, and wrapping itself around trees, rose bushes or virtually anything else that is in their path and standing still.
The Wisteria is a genus of flowering plants in the legume family Fabaceae. The genus includes about 10 species of woody climbing vines native to East Asia and North America. So, in fact, the wisteria is closely related to other legumes like peas, beans, and clover!
A word to the wise: While the Wisteria tree is renowned for its beauty, it is highly toxic. All parts of the Wisteria plant contain toxins, with the seeds and pods being the most potent. The primary toxic compounds are wisterin and lectin, which can cause severe gastroenteritis if ingested. Symptoms may include nausea, vomiting, stomach pains, and diarrhea. In severe cases, particularly if many seeds are consumed, it can lead to dehydration, collapse, and in rare instances, death. This toxicity is especially concerning for households with curious pets or young children who might be tempted to sample the attractive-looking pods or seeds. So if you were thinking of growing your own, be extra careful.
Wisteria offers a diverse array of cultivated varieties, each with unique characteristics that appeal to different gardeners and landscapers. The Chinese Wisteria (Wisteria sinensis) and Japanese Wisteria (Wisteria floribunda) are among the most popular species for cultivation. Notable varieties include the 'Alba', which produces stunning white racemes, and the 'Rosea', known for its delicate pink flowers. The 'Longissima' variety of Japanese Wisteria is prized for its exceptionally long flower clusters that can reach up to 1.5 meters in length. For those seeking unusual colors, the 'Violacea Plena' offers double purple flowers, while the 'Kuchi-beni' features unique bi-colored blooms with purple buds opening to white flowers tinged with lilac.
American Wisteria (Wisteria frutescens) varieties like 'Amethyst Falls' are gaining popularity due to their more manageable growth habits and resistance to cold. Each variety not only differs in flower color and cluster length but also in blooming time, fragrance intensity, and growth characteristics, allowing gardeners to choose the perfect Wisteria for their specific needs and preferences.
