Kudzu is a perennial invasive vine that smothers other vegetation, including native plants. Introduced originally from Asia as a landscape ornamental in the 1870s, it was promoted to combat erosion in the southeastern United States in the 1930. Semi-woody, slightly hairy stems are covered with trifoliate leaves in dark green. Kudzu vines grow quickly and can reach up to 100 feet in length, crawling into the crown of the tallest trees and depriving them of light, choking them, or making them collapse from sheer weight. It can also engulf man-made structures such as power lines, road signs, and buildings. For homeowners, it is crucial to identify and control kudzu early on—once it has taken hold, it's very difficult and lengthy to eradicate.
|Common Name||Kudzu, East Asian arrowroot|
|Botanical Name||Pueraria montana var. lobata|
|Plant Type||Perennial, vine|
|Mature Size||60-100 ft. long|
|Soil Type||Sandy, well-drained|
|Hardiness Zones||5–10 (USDA)|
Invasiveness of Kudzu
Kudzu is an invasive species mainly in the eastern United States. It was introduced to the United States from its native Asia (Japan and China) in 1876. For a long time, it was viewed as a “wonder plant"—in fact, in the 1930s, the government paid landowners in the southeastern United States $8 per acre to plant kudzu for erosion control and cattle grazing.
It was estimated in 2001 that kudzu covers more than five million acres of forest land, which is more than five times the size of the state of Rhode Island. Known as "the vine that ate the South," kudzu is mainly found in the southeastern United States but has also been reported in northern states like Pennsylvania. It can thrive and establish itself year-round in most locations.
Kudzu spreads primarily through runners, rhizomes, and vines, though it can also be dispersed through seeds. Kudzu overgrows anything in its way, blocking sunlight and depriving nearby plants of water and nutrients until they die. It girdles tree trunks and can break branches and whole trees due to its immense weight.
Kudzu develops a huge tuberous taproot up to 13 feet long, which alone can weigh close to 400 pounds. The vine is mainly found on non-cultivated land such as abandoned fields, ditches, and along roadsides, and in open space or woods.
By killing plants that serve native wildlife species as food and shelter, this invasive plant poses a major risk to biodiversity, especially in the southeastern United States.
What Does Kudzu Look Like?
Kudzu vines are hairy and semi-woody deciduous vines. Up to 30 vines can grow from a large, central root crown. In warm climates, the stems can grow up to one inch or more in diameter and 60 to 100 feet long.
The leaves are alternate and compound, with three dark green oval or heart-shaped leaflets, each 3 to 4 inches long. The underside of the leaves has small white hairs.
Kudzu can grow in the sun or shade but you will find it flowering mostly in locations with full sun. It flowers from mid to late summer. The flowers, which grow in elongated clusters, are purple and pea-like with a grape-like scent.
The fruits give away that kudzu is a member of the pea family (Fabaceae). They grow in hairy pods in clusters and look like beans. The brown, kidney-shaped seeds inside the pods have a low germination rate; most new growth comes not from seeds but from asexual propagation.
Wherever the stem nodes of a vine have soil contact, they form adventitious roots, and over time these become independent plants. That leads to the typical curtain- or mat-like vigorous growth habit of kudzu.
How to Get Rid of Kudzu
Unfortunately, there aren't any quick or easy ways to get rid of kudzu—that is, unless you keep goats or sheep on your property, as they love to eat the vine. Most herbicides, including those with glyphosate as the active ingredient (Roundup), have a limited effect on the plant, and only when it's fairly small. Kudzu is also fire-resistant, so burning the roots will only weaken the plant, not eradicate it. There are two different mechanical ways to tackling a kudzu infestation—above ground and below ground—and both require diligence and persistence.
Above ground, start by cutting the vines at ground level, then follow your efforts up with the regular mowing or hand-cutting of any emerging shoots until there is no more new growth. Kudzu is weakened over time by repeated defoliation, but you may have to do this weekly during the growing season for up to two years until the vine is fully gone. Make sure to safely dispose of all the cut plant parts in a sealed garbage bag.
Additionally, kudzu sends out new growth from the root crown but not the entire root below it. For this reason, removing the root crown is crucial. To do so, cut the root just below the root crown using a handsaw or pruning shears (depending on the size). If the root crown is still intact, or if any vines are left in the soil, kudzu will grow back.
It’s important to keep a close eye on the affected area for a couple of years before you declare a victory over kudzu. An equally important task is to replant the area with a desirable landscaping plant to help fill in space. Do not leave the land bare—this can increase the risk of kudzu returning and re-establishing itself.
Are there different types of kudzu?
There are three subspecies of Pueraria montana. The subspecies with lobed leaves (var. lobata) is the most common.
How fast does kudzu grow?
An established kudzu plant can add up to 1 foot in length per day.
Is kudzu toxic to humans?
The plant is edible and not toxic to humans.
Pueraria montana var. lobata. North Carolina State University Cooperative Extension.