Kudzu (Pueraria montana var. lobata) is a climbing, semi-woody, perennial vine in the pea family (Fabaceae).
Deciduous leaves are alternate and compound, with three broad leaflets up to 4 inches across. Leaflets may be entire or deeply 2-3 lobed with hairy margins. Individual flowers, about 1/2 inch long, are purple, highly fragrant and borne in long hanging clusters. Flowering occurs in late summer and is soon followed by production of brown, hairy, flattened, seed pods, each of which contains three to ten hard seeds.
Native to eastern Asia, this invasive vine has colonized much of the southeastern United States, infesting approximately 30,000 sq. km. per year at a cost of over $500 million per year to the US economy in the form of lost crop and forests productivity, expenditures for control, and damage to property. Kudzu kills or degrades other plants by smothering them under a solid blanket of leaves, by girdling woody stems and tree trunks, and by breaking branches or uprooting entire trees and shrubs through the sheer force of its weight.
Once established, kudzu plants grow rapidly, extending as much as 60 feet per season at a rate of about one foot per day. This vigorous vine may extend 32-100 feet in length, with stems 1/2 to 4 inches in diameter. Kudzu roots are fleshy, with massive tap roots 7 inches or more in diameter, 6 feet or more in length, and weighing as much as 400 pounds. As many as thirty (30) vines may grow from a single root crown. Not surprisingly, kudzu is considered one of the 100 worst bioinvaders in the world.
It was first introduced into the U.S. in 1876 at the Philadelphia Centennial Exposition, where it was promoted as a forage crop and an ornamental plant. From 1935 to the mid-1950s, farmers in the south were encouraged to plant kudzu to reduce soil erosion, and Franklin D. Roosevelt's Civilian Conservation Corps planted it widely for many years.
For successful long term control, its extensive root system must be destroyed, as any remaining root crowns can lead to reinfestation of an area.