Origin: Eastern Asia
Introduction: 1899 (ornamental, agriculture)
An estimated 2 million acres of forest land in the southern United States is covered with kudzu. Kudzu was promoted as a forage crop and an ornamental plant when it was introduced to the U.S. at the Philadelphia Centennial Exposition in 1876. Many southern farmers were encouraged to plant kudzu for erosion control from the mid 1930’s to the mid 1950’s. In 1953, kudzu was removed from the US Department of Agriculture’s list of permissible cover plants due to its recognition as a pest species. Currently in Florida, kudzu has been documented in 14 counties and is listed as a Category I invasive species.
Kudzu is a climbing, semi-woody, perennial vine in the legume family that has the potential to reach up to 100 feet in length. Stems can reach the diameter of ½ to 4 inches, but there are report of old ‘stumps’ nearly 12 inches across in Georgia. Alternately arranged leaves are compound with three broad leaflets up to 4 inches across. Leaflets may be entire or deeply 2-3 lobed with hairy margins. Flowers are ½ inch long, purple, highly fragrant and borne in long hanging clusters. Flowering occurs in late summer, followed by the production of brown, hairy, flattened, seed pods that contain three to ten seeds.
Kudzu will grow over anything in its path (other plants, buildings, road signs) and eventually kill other plants it covers because it blocks out sunlight. Kudzu will also girdle stems and tree trunks, break branches, and uproot trees and shrubs through the masses of vegetation produced. Kudzu has been reported to grow roughly one foot per day once established.
Total eradication of kudzu is necessary to prevent re-growth. This requires continuous monitoring and thoroughness when treating. To prevent reestablishment, replanting after treatment is critical. Prevent the production of viable seed and destroy the plant's ability to reproduce vegetatively.
Young colonies can be eradicated in three to four years if plants are overgrazed or persistently cut back repeatedly during the hottest temperatures of summer. Close grazing for three to four years can totally eliminate kudzu when at least 80% of the vegetative growth is continuously removed by livestock. An old rule of thumb is 8 goats per acre stocking rate for kudzu control.
The massive root system and crowns must be destroyed for long term control of kudzu. Cut vines just above ground level and destroy all cut material. Close mowing every month for two growing seasons or repeated cultivation may be effective. Pre-burning, cutting, hand digging and disking will weaken the roots and aid in control when used in conjunction with herbicides.
Biological control agents are being investigated, but the recent introduction of asian soybean rust is thought to be very devastating to kudzu.
Glyphosate, chlopyralid (Transline), metsulfuron (Escort) and aminopyralid (Milestone VM) can be used to control kudzu. Follow label directions and precautions.