With its drooping panicles of pastel blossoms, draping old porches or arbors, wisteria has always seemed like one of those romantic and beautiful plants no garden should do without. I've never had one... until this year.
Last spring, I planted a small wisteria vine I bought from a local nursery, and planted it next to our latticed fence, near the front gate. Already, in my mind's eye, it has grown to cover the fence, to hang its long pendants of sweet-pea like flowers over the entrance to our yard.
In real life, it's only about three feet tall, but it's reaching out and up, starting to climb up the fence. It even has put forth one small panicle of lavender blooms.
There are eight to ten species of wisteria available, but four are the most readily found in nurseries.The most familiar ones are the two Asiatic species.
Chinese wisteria (Wisteria sinensis) has lilac-blue flowers in foot long racemes in May, blooming just before the compound leaves emerge. It is the strongest climber of all the wisterias, and can easily reach 100 feet.
Japanese wisteria (W. floribunda) is more fragrant than the Chinese variety. The flowers appear with the leaves, with clusters of flowers up to 2 feet long. The Japanese wisteria can be found in three main cultivar colors - ivory, reddish-violet, or pink.
Both these Asiatic wisterias grow quickly and agressively. The vines will grow thick and gnarled in time, and need a very strong support.
Native American species
Two native American wisteria species are good choices for southern gardens.
W. fructescens is native from Virginia to Florida, and west to Texas. It has much shorter flower racemes - 2 - 5 inches long, and smaller leaves. W. macrostachya is native to Kentucky and the Mississippo valley. It's lilac-purple blooms are the latest flowering. Both of these vines are less rampant, and generally will bloom faster than the Asiatic varieties.
Young plants may need a good steady supply of water, but mature specimens can be quite drought-tolerant. The vines will grow in many soil types. Because they, like legumes, produce nitrogen, the soil doesn't need to be rich. They do best in full sun.
Stake your young plants until they are established, and can be attached to a permanent support. Because of their vigorous growth and climbing habits, you'll have to find the right site for wisteria. It will require a sturdy trellis, an arbor, or a pergola for support. It is possible to train wisteria like a tree, but they will have to be carefully pruned and trained.
A Wisteria Bonsai
Pruning and Training for Bloom
The key to getting a wisteria to bloom is to have conditions less than favorable. If the soil is too nitrogen-rich, or it has too much water, it will grow well, foliage wise. However, if the roots are restricted, or nutrients depleted, the plant will switch to its reproductive stage, and bloom well. It is also possible to prune the roots, by using a spade to cut the more surface roots about 2 feet out from the main trunk.
You'd better be a 'hands-on' gardener if you want a wisteria in your yard. Pruning is necessary to direct and control the sometimes rampant growth. Prune it in the winter, leaving some of the last year's growth, as that's where the flowers form. If it gets too wild in summer, you can prune it, but don't over-do it. Too much pruning will encourage vegetative top growth.
Wisteria: A Comprehensive Guide
Wisteria require yearly care and control, but when planted in a good location with a sturdy support, a wisteria vine can be a lovely addition to the landscape.
There is no other flowering vine quite like it. In May, when the lavender blossoms cascade from the pergola or porch, and send out a soft fragrance in the air, you just may find yourself under the spell of this appealing and beautiful vine.
© 2009 Nicolette Goff