Plant of the Month: Wisteria

Showy spring flowers of Wisteria droop and dangle down to provide an ideal backdrop for the perfect fairy tale ending, replete with flowery fairies. Clusters of these fragrant blossoms (racemes) come in deep purple, blue, rose and white. In the summer, older vines, with their thick, woody, twining vines produce a cooling canopy of feathery leaves to block the searing sun.

Although most people believe Wisteria to be from Asia, two varieties are native to the Eastern United States: American wisteria (W. frutescens) and Kentucky wisteria (W. macrostachya).

Pruning of this hardy and fast growing vine is highly recommended. Though it is uncommon to get so large, the world's largest known Wisteria covers an acre of land in Sierra Madre, California. Yikes. If not trimmed, Wisteria vines and branches are able to pull off siding and shingles, strangle a mature tree and crush lattice. Wisteria vines require a strong supporting structure, such as a wall, or pergola.

Before planting wisteria, plan well, for these plants are long lived. Once established, Wisteria spreads through root shoots which can travel almost 50 feet. Once you decide upon its boundaries, cut along that boundary with a spade to prevent Wisteria's powerful underground shoots from spreading. The powerful roots can crack a sidewalk or driveway.

To discourage Wisteria from growing into a mound and to encourage a central vine, clip back shoots that come up close to the main vine..

Too much fertilizer, specifically nitrogen, will inhibit blossoms. Unless deadheaded, clusters of pods will form after Wisteria blooms are spent. When the pods dry up, their seeds may be cast as far as 20 feet from the parent vine. Avoid new plants sprouting by raking out the pods before they open. Its poisonous seeds have been known to sprout from compost piles. Only the most patient gardener can wait 10 or 15 years for wisteria grown from seed to bloom. Quicker ways are to buy plants grafted onto root stock or from a cutting.Two interesting poems inspired by Wisteria: Of Twisting Vines, and The Purple Blossom Wisteria Vines.