Japanese wisteria is a beautiful vine in flower, but it is an aggressive grower and is considered invasive in some areas, especially in the southern United States. A review of risks should be undertaken before selecting this vine for planting sites.
Size and method of climbing:
Japanese wisteria can grow 30 feet or more. It is a twining vine which climbs by twisting its stems or leaf stalks around a support. This type of vine grows well on trellises, arbors, wires, or chain-link fences.
Native geographic location and habitat:
It is native to Japan.
Leaf description:
The opposite leaves are pinnately compound, with 13 to 19 leaflets.
Flower description:
It produces violet, pea-type flowers in dangling clusters. The clusters are 8 to 20 inches long, light in fragrance, and are produced in mid to late spring.
Fruit description:
Fruit is similar in appearance to pea pods. Seeds are poisonous to eat, as are other parts of the plant.
Plant care:
Full sun is preferable with a moist, well-drained soil. Japanese wisteria is adaptable to a range of soil pH. Wisteria often do not produce flowers for the first five to ten years. To encourage flowering, use nitrogen fertilizer sparingly and also use a fertilizer that provides phosphorus (follow label directions). Proper pruning will also encourage flowering. After flowering, prune excess growth back to 6 inches. These pruned stems will continue to grow. In winter cut them again so that each stem has two to three buds left. Proper pruning not only encourages flowering, but it also helps to manage the size and shape of the vine. Wisteria vines are heavy and require sturdy supports.
List of pests, diseases, tolerances, and resistance:
No serious pests, but this plant is an aggressive grower and has become invasive in some locations. Tolerant of black walnut toxicity.
Honbeni Japanese wisteria (Wisteria floribunda ‘Honbeni’):
This is a cultivar with soft pink flowers.
Issai Perfect Japanese wisteria (Wisteria floribunda ‘Issai Perfect’):
A very fragrant cultivar with white flowers.
Lawrence Japanese wisteria (Wisteria floribunda ‘Lawrence’):
A cultivar with pale, lavender-blue flowers.
Longissima Alba Japanese wisteria (Wisteria floribunda ‘Longissima Alba’):
A cultivar with white flowers produced in longer clusters of 18 to 24 inches.
Royal Purple Japanese wisteria (Wisteria floribunda ‘Royal Purple’):
Dark purple, double flowers.
Shiro Noda Japanese wisteria (Wisteria floribunda ‘Shiro Noda’):
White flowers.
Violacea Plena Japanese wisteria (Wisteria floribunda ‘Violacea Purple’):
Blue-violet, double flowers.
