Blue Flowering Wisteria

Wisteria is a time-honored vine that is almost synonymous with cottage garden designs. Blue Flowering Wisteria is the most cold-tolerant and easy-to-grow variety available. Wisteria macrostachya, also known by the common name Kentucky Wisteria, is a North American native plant, ranging from Illinois to Texas in the south-central portion of the United States. The vividly blue racemes of flowers bloom early in the spring before the foliage emerges. Often, a lighter second flush of flowers appears after midsummer.

Pollinators, especially early native bees and hummingbirds, are drawn to the fragrant flowers, while the dense foliage is the perfect shelter and safe haven for other beneficial insects late in the summer. Deer rarely browse on Wisteria as all parts are poisonous to most animals. Take care and wear gloves when pruning and planting Wisteria, as the white sap that flows from pruning cuts is toxic and irritating for some people. Wisteria is in the legume (pea) family and capable of transferring nitrogen from the air to nodules that form on its roots, meaning that this plant rarely needs fertilizing. 

Blue Flowering Wisteria Care

Wisteria is versatile and grows in full sun to partial shade, but performs best in full sun. Slightly acidic to neutral soil that is also fertile and moisture will produce the most vigorous growth and best flower and foliage color. Annual mulching with 2-3 inches of organic compost will suppress weed growth and aid in moisture retention. 

Water the vine well until it is established, which can take 1-3 years. Once Wisteria is fully established, it is typically drought tolerant, requiring little supplemental watering during the growing season. Fertilize after the initial flowering period if the foliage begins to yellow. Use a granular, slow-release formulation for acid-loving shrubs and perennials, and apply it as a top dressing over the root zone.

Pruning is the key to a well-blooming Wisteria vine. Even though other Wisteria varieties are notoriously slow to flower, Wisteria macrostachya will flower within 2-3 years of planting (albeit lightly for a few years). Cut back growth hard in the late summer or early fall. This sets up the vine to produce a large amount of flowers and keeps the overall growth tamed. Cutting all excess stems back to 3-4 leaf buds will spur bud development in the spring. During the growing season, regularly cut back wayward stems and excessive sucker growth at the soil level at any time. 

Blue Flowering Wisteria Spacing

Wisteria vines can reach 25 feet long with a width of 8 feet at the base. Provide a sturdy structure during the initial planting so that the fast-growing vines can be tied and trained to twine. Grow shallow-rooted shrubs, perennials, and annuals as an understory, spacing plants at least 16 inches from the main trunk.

Blue Flowering Wisteria Information