Any mention of wisteria vines conjures up images of trellises down South, hanging heavily with the long, pendulous, deep lavender or purple flower clusters. The wisteria species that thrive in southern climates aren’t winter-hardy enough to survive in the Upper Midwest.
Over the years, several wisteria varieties have been sold and planted in our region, particularly the varieties Aunt Dee and Blue Moon. But they’ve met with variable success. Although these types often survive winter, they can be very slow to begin flowering, sometimes taking up to ten years, flowering only on very old wood.
A new wisteria has been recently introduced by the University of Minnesota, and it looks very promising for northern growing conditions. It’s called Summer Cascade wisteria, and the U of M is considering it the first wisteria reliably hardy to zone 3.
Here’s what the U of M is saying about the new wisteria: “The hardy ‘Summer Cascade’ wisteria was bred from a hardy strain of Kentucky wisteria and first known as ‘Betty Matthews,’ after a White Bear Lake MN resident in whose yard it grew. It blooms on new growth in June. Individual flowers are borne on long showy racemes and open as a lovely shade of dark lavender before fading. This beautiful flowering vine thrives in full sun, and can easily cover an arbor or pergola to create a shady retreat. An interesting seed pod in late summer provides multi-season interest.”
They continue “Carefully consider where to place a new wisteria. It can be an aggressive grower that develops a heavy wood structure of its own. Supports such as a fence, arbor or trellis must be able to accommodate that weight. Once established, new canes can grow up to 10 feet in a summer. Routine pruning several times throughout the growing season will restrain its size and promote blooms. Prune two or three times throughout the summer to prompt blooms. It is proven hardy to Zone 3.”
Summer Cascade wisteria is being sold under the First Editions brand, and propagated by the wholesaler Bailey Nurseries of St. Paul, from where it will be distributed to local garden centers. I’m sure we’ll have to do some shopping around, as the supply of new items is often limited until they become widely available. I’ve put this on my must-try list.