Do Wisteria Vines Spread?

Characteristics

• Wisteria vines are part of the pea family. The genus, Wisteria, includes 10 species of climbing vines, two of which are native to the southern United States. Their blooms may be white, pink, lilac-blue, bluish-purple and purple. They grow to be about 25 feet and can be trained to grow vertically or horizontally. If left unattended spreading wisteria vines can smother trees and cause serious structural damage to homes.

Growth

• Wisteria are champion growers and they send out new runners every summer. Some grow out of the main trunk and others come up from underground. Over 90 percent of new growth, according to online resource Plantamnesty.com, should be pruned off as it grows in the summer, so the plant doesn't take over your yard or house. Plantamnesty.com also says that a single runner can grow about 12 feet in a year and monthly attention to summer runners is absolutely necessary in order to keep the plant in control.

Support

• Proper support is necessary for controlling a wisteria vine. Vines left to their own devices will quickly take over structures and surrounding vegetation. If you have a plan for its growth you'll know what to prune in order to stop the inevitable spread. Wisteria plants can become quite heavy and will need sturdy support as they grow. Wires, trellises, arbors and pergolas can all provide adequate support. Vertical rows of wire securely attached to a wall will help wisteria spread in a controlled manner. Use pressure-treated wood for arbors and pergolas and be sure that long, trellising branches will not clog gutters. Wisteria can be grown in an upright tree position as well. Just stake it and cut the top off when it gets to around 6 feet. You'll need to pay special attention to shoots popping up near the tree if you choose this form.

Pruning and Training

• Pruning is essential to proper growth and flowering. Only allow one strong leader vine per support. Cut all new leader vines at the sixth or seventh leaf in the summer. During late winter cut leader shoots back to one-half or two-thirds their length and cut side shoots back to 1 to 2 inches. To train a new vine select an upright stem and attach it to the support. Continue to train the main leader and side shoots necessary to fill the framework's space. Because wisteria spread so rapidly, they are considered invasive by the U.S. Forest Service. Keep this in mind as you prune. You'll need to put in many hours of pruning time to ensure this vigorous grower doesn't take over your property.