AUBURN, Ala. — If you have driven along the interstate, then you have likely seen the beautiful purple flowers clustered on a green, leafy vine. While many consider this vine, wisteria, beautiful, it can cause quite the problem for home gardeners.
What to Know About Wisteria
Wisteria is a vine that grows across Alabama and much of the Southeast. Some varieties of the vine are non-native and invasive. Without careful control, the fast growing and aggressive plant can quickly take over and kill native plants.
The Early Detection and Distribution Mapping system shows it grows in USDA hardiness zones 5 through 9. To find what zone you are in, visit the USDA Plant Hardiness Zone Map.
Lucy Edwards, an Alabama Extension agent for home grounds said the plant can spread quickly via seeds.
“The seeds are very viable, and they germinate very easily,” she said.
Multiple species of the vine can be found in many areas. The non-natives are Chinese Wisteria (Wisteria sinensis), Japanese Wisteria (W. floribunda) and evergreen wisteria (Millettia reticulata). The native wisteria species is the American Wisteria (W. frutescens).
According to Dr. Nancy Loewenstein, an Alabama Extension forestry specialist, it can be difficult to identify the actual species of the invasive types.
“Many infestations that grow rapidly are actually a hybrid of Japanese and Chinese types,” said Loewenstein.
If you are looking for a good vine to cover your pergola or to provide shade the native option is a better choice.
“They have a cultivar of American wisteria called ‘Amethyst Falls’ that is a native,” says Edwards. “I recommend it for homeowners planting”.
In addition, the native species attracts butterflies. It serves as a host plant for silver-spotted skipper and the long-tail skipper butterflies larva.
It is important to remember that you still have to prune your native species.
Edwards said that the best time to plant is in the fall, allowing for root development before spring growing season begins.
Getting Rid of Non-Natives
According to Loewenstein, wisteria spreads by more than just seeds. Individual plants can spread through their vines as they run along the ground. The vines can root at the leaf nodes and eventually create a new independent plant.
Loewenstein said one way to control wisteria in an urban setting is by cutting the vine and then immediately putting a herbicide on the stump before it hardens. She warned that wisteria is notoriously difficult to control and as a result, follow-up treatments will likely be necessary.
Finally to learn more about controlling invasive plants, visit http://www.aces.edu/pubs/docs/A/ANR-1465/ANR-1465-low.pdf.
Wisteria images by Bruce Dupree/Alabama Extension.