David Moorhead
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Kudzu
Pueraria montana
Origin: Asia
Background
Kudzu was introduced into the United States from Japan in
1876 at the Philadelphia Centennial Exposition, where it
was promoted as an ornamental and a forage crop plant.
From 1935 to the mid-1950s, farmers in the South were
encouraged to plant kudzu to reduce soil erosion, and the
Civilian Conservation Corps planted it widely for many
years. Kudzun nicknamed "the vine that ate the
south," was eventually recognized as a pest weed by
the U.S. Department of Agriculture and, in 1953, was
removed from its list of permissible cover plants.
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Kerry Britton
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Distribution and Ecological Threat
Kudzu is common throughout most of the southeastern United
States and in recent years has been found in northern
states as well. It is apparently able to withstand harsher
winter conditions than previously thought. Kudzu grows
well under a wide range of conditions and in many soil
types. Preferred habitats are open, sunny areas like
forest edges, abandoned fields, roadsides and disturbed
areas. Kudzu grows best where winters are mild, summer
temperatures are above 80 degrees Fahrenheit and annual
rainfall is 40 inches or more. Its vigorous growth and
large leaves smother native plants; its vines kill trees
through girdling and the added weight of vines can lead to
uprooting trees. Once established, kudzu plants grow
rapidly, extending as much as 60 feet per season, at the
astonishing rate about 1 foot per day.
Description and Biology
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Plant: a climbing perennial vine in the pea family
(Fabaceae); vines may extend 32 to 100 feet in length,
with stems up to 4 inches in diameter. Roots are
fleshy, with massive tap roots 7 inches or more in
diameter, 6 feet or more in length, and weigh as much
as 400 pounds; 30 vines may grow from a single root
crown.
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Leaves: deciduous leaves are compound, with three broad
leaflets up to 4 inches across; leaves alternate along
stem; leaflets may be entire or lobed with hairy
margins.
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Flowers, fruits and seeds: individual flowers, about
1/2 inch long, are purple, fragrant and borne in
upright clusters during late summer. Fruits if present
are brown, hairy, flattened seed pods, each of which
may contain up to ten hard seeds.
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Spreads: mainly vegetative through expansion by runners
and rhizomes and by vines that root at the nodes to
form new plants; may spread by seeds in areas where a
pollinator, the giant resin bee, occurs.
Jil Swearingen, NPS
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David Moorhead
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Prevention and Control
For successful long-term control of kudzu, the extensive
root system must be destroyed. Any remaining root crowns
can lead to reinfestation of an area. Mechanical methods
include cutting vines just above ground level, frequent
mowing and cultivation. Use of systemic herbicides is the
most effective and practical method currently employed.
The federal government is investigating biological control
agents for kudzu.
Native Alternatives
After eradicating, plant area with native vegetation
appropriate to site conditions. Refer to
References.
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