Name: Pueraria montana
Native Range: Kudzu is found throughout Asia, including China, Korea, Japan, Taiwan, Indonesia, Malaysia, Papua New Guinea, Philippines, Thailand, and Vietnam. It is also native to the south Pacific region, including Australia, Fiji, New Caledonia, Solomon Islands, Tonga, and Vanuatu.
Introduction: Americans were first introduced to kudzu at the Centennial Exposition in Philadelphia in 1876, where gardeners and hobbyists marveled over a garden featuring plants from Japan. Known as “mile-a-minute” vine, kudzu’s fast-growing tendencies and strong root system made it an appealing tool for farmers and ecosystem managers. By the early 1900s, use of kudzu was already widespread—the Soil Conservation Service even hired hundreds of men to plant kudzu for erosion control in the 1930s. By the 1940s, the government was paying farmers in the south to plant the vine by the acre.
People experimented with a wide variety of ways to use kudzu. In addition to erosion control, kudzu could be used as livestock feed or to make baskets or paper. Kudzu has even been shown to possess medical properties and was used to fight inflammation and infections, among other ailments.
Now, kudzu is most commonly found in the U.S. south, but its range stretches north towards New York and west towards Texas.
Why are they harmful?: All of the reasons people were originally attracted to this creeping vine make it an incredibly damaging invader. Known to grow a foot a day in the summer season, kudzu vines grow up to 100 ft long and can quickly smother trees, houses, power lines, and anything else that stands in its way. Tolerant to both drought and frost, its hardiness allows it to remain dominant and outcompete other plants.
Forests can be completely overrun by the plant in as little as two or three years, resulting in lower biodiversity and productivity.
Methods of control: Controlling this widespread invader isn't easy. To effectively eradicate it from an area, its complicated root system must be destroyed. Many states have tried herbicides with varying results—it can take up to ten years of repeated application to finally kill a kudzu plant. Diligent mowing and grazing is the best bet to weaken the plant—management initiatives using cattle, goats, and sheep to graze the plant have been successful if applied over many growing seasons. People should use caution when mowing patches of kudzu though, as its dense, tangled vines could obscure ditches and other hazards.
Sources: Columbia University, Nature Conservancy
Photo credit (cover photo): Katie Ashdown / Flickr