Les Harrison is the UF/IFAS Wakulla County Extension Director
The sweet smell of spring is here, in part to the abundance of Japanese wisteria covering the trees in the area. The kudzu-like invasion of this flowering vine can be detrimental to many of the native species of plants and trees inhabiting Wakulla county.
American wisterias cone-shaped blooms produce a more subtle scent, but the plants growth is more subdued and easier to control.
Japanese Wisteria (Wisteria floribunda) is blooming plentifully from every tree, fence and any other structure it is able to climb.
There are 10 species identified as Wisteria in this genus, with Wisteria floribunda native to Japan. Other members of this genus originate in China, Korea and even the eastern United States.
In its native range, Wisteria floribunda is prized for its hardiness and flowering capacity. It produces the largest flowers in it genus, and they have a pleasant scent. The vine was imported into the U.S. during the 1830s when Japan was still a closed society. Its tolerance of a wide range of environmental conditions and profuse lavender blooms made it an ornament in high demand.
Growth of the Wisteria vine is usually limited only to the height of the plant or structure it is climbing on. It is not uncommon to see it grow more than 65 feet in height. Flowering occurs through May with velvety brown seedpods produced soon after. The pods are four to six inches long with black or dark brown butterbean shaped seed which are toxic to mammals.
The problem with Wisteria is its growth pattern. Wisteria floribunda is a vine which will grow virtually up anything in its path and, curiously enough, grow in a clockwise configuration. By climbing into the canopy of trees or plants, it can shade them out, impairing those plants from effectively growing. Over time, Wisteria will climb and twine around other plants, eventually shading and girdling native plants.
As a result of this aggressive and destructive behavior, Wisteria floribunda has been labeled a category II invasive exotic by Florida Exotic Pest Plant’s Council. This designation indicates the adverse effects on Florida’s biodiversity and native plants, and the need for pest plant management. A category II invasive exotics is a plant which has increased in abundance or frequency, but has not yet altered Florida plant communities to the extent shown by category I species. Category I species have altered native plant communities by displacing native species, changing community structures or ecological functions, or hybridizing with natives.
American Wisteria (Wisteria frutescens) looks similar to its Japanese cousin, and grows well, but not overly aggressively, in North Florida. This native plant is a vine with somewhat more subdued blooms, but is used in ornamental applications with fewer control challenges.
For more information on selection, planting, and caring for vines, read the UF/IFAS publication, Flowering Vines of Florida.
To learn more about Wisteria and other flowering vines in Wakulla County, contact your UF/IFAS Wakulla Extension Office at 850-926-3931 or http://blogs.ifas.ufl.edu/wakullaco/