Kudzu

Pueraria montana var. lobata

Identification

Appearance

Kudzu is a climbing, deciduous vine capable of reaching lengths of over 60 feet in a single season.

Foliage

Leaves are alternate, compound (with three, usually lobed, leaflets), hairy underneath and up to 5 inches. 

Flowers

Flowering occurs in midsummer, when 0.5 in. (1.3 cm) long, purple, fragrant flowers hang, in clusters, in the axils of the leaves.

Fruit

Fruit are brown, hairy, flat, 3 in. (7.6 cm) long, 0.3 in. (0.8 cm) wide seed pods.

Biology

Origin

Native to Japan/China, kudzu was introduced to U.S. in 1876 as ornamental and intentionally spread in the Dust Bowl Era for erosion control. Generally spreads through vegetative means (runners); can also spread through seeds, altough this is less common.

Habitat

Forest edges, roadsides, abandoned fields and disturbed areas in almost any soil type. Prefers full sun.

ECological Threat

Kudzu is a landscape threat because it smothers other plants with a dense blanket of leaves and girdles or uproots trees. It is known as “the vine that ate the South”. Kudzu is not established in Vermont, but poses a significant threat to the state’s ecosystems and agriculture. With increasingly milder winters, kudzu may be able thrive in many parts of Vermont. Kudzu can grow in a wide range of soil types and appears acclimated to neighboring northeastern states. Because it is a legume and fixes its own nitrogen, it can rapidly outcompete native plants in poorer soils, creating a virtual monoculture.

Management Options

The best way to protect against the damage caused by kudzu is to prevent its introduction. Kudzu primarily spreads vegetatively (runners & rhizomes) but also can spread though seed. Soil should not be transported from infested areas and any transplanted plants should be bare rooted; nursery owners should carefully monitor new stock. Equipment and tools should be thoroughly cleaned after being used in kudzu invaded areas. Stone or wood products could be a pathway of spread if they have viable vines or seeds on them. 

Once established, Kudzu is extremely difficult to eradicate even with chemical means. It may take 5 to 10 years of intense effort to eradicate a mature population. The main reason that kudzu is so difficult to eradicate is that it has a massive root/rhizome system that stores large amounts of starch and can regrow new shoots rapidly if the tops are removed. If using herbicides, they should be applied multiple times during the growing season to deplete the rhizome storage. Smaller populations can be mowed or cut every two weeks while actively growing; all plant crowns must be cut so that the vine network is depleted. Cut material should be disposed of by burning or landfilling. In some cases, intensive grazing by goats or sheep can reduce long-term growth.

Vermont Distribution

According to EDDmaps, kudzu is confirmed in 33 states and Ontario, Canada (see map). The majority of the infestation is in the Southeastern states. It is not known to be in Vermont.

How You Can Help

Kudzu is on the early detection list of plant species. Early detection of new infestations increases our ability to slow their spread and potentially eradicate them from affected areas.

Report an observation

Citations

Photo Credit

Kudzu images (5483269, 5483466, 2307160, 5483472, 5483266, 5483458) Leslie J. Mehrhof, Bugwood.org

Kudzu infestation, 0002156, Kerry Britton, Bugwood.org

Poison ivy, 5584737, Steven Katovich, Bugwood.org

American hogpeanut, 5556461, Steven Katovich, Bugwood.org 

Grape foliage,1556201, Ohio State Weed Lab, Bugwood.org

 

Information Credit

Center for Invasive Species and Ecosystem Health

VT Agency of Agriculture, Food and Markets