Kudzu (Pueraria montana var. lobata) is a climbing, semi-woody, perennial vine in the pea family (Fabaceae).

Deciduous leaves are alternate and compound, with three broad leaflets up to 4 inches across. Leaflets may be entire or deeply 2-3 lobed with hairy margins. Individual flowers, about 1/2 inch long, are purple, highly fragrant and borne in long hanging clusters. Flowering occurs in late summer and is soon followed by production of brown, hairy, flattened, seed pods, each of which contains three to ten hard seeds.

Native to eastern Asia, this invasive vine has colonized much of the southeastern United States, infesting approximately 30,000 sq. km. per year at a cost of over $500 million per year to the US economy in the form of lost crop and forests productivity, expenditures for control, and damage to property. Kudzu kills or degrades other plants by smothering them under a solid blanket of leaves, by girdling woody stems and tree trunks, and by breaking branches or uprooting entire trees and shrubs through the sheer force of its weight.

Once established, kudzu plants grow rapidly, extending as much as 60 feet per season at a rate of about one foot per day. This vigorous vine may extend 32-100 feet in length, with stems 1/2 to 4 inches in diameter. Kudzu roots are fleshy, with massive tap roots 7 inches or more in diameter, 6 feet or more in length, and weighing as much as 400 pounds. As many as thirty (30) vines may grow from a single root crown. Not surprisingly, kudzu is considered one of the 100 worst bioinvaders in the world.

It was first introduced into the U.S. in 1876 at the Philadelphia Centennial Exposition, where it was promoted as a forage crop and an ornamental plant. From 1935 to the mid-1950s, farmers in the south were encouraged to plant kudzu to reduce soil erosion, and Franklin D. Roosevelt's Civilian Conservation Corps planted it widely for many years.

For successful long term control, its extensive root system must be destroyed, as any remaining root crowns can lead to reinfestation of an area.

A native of Asia, Kudzu (Pueraria montana var. lobata) is among the most widespread and abundant invasive weeds in the eastern United States. Although its stronghold in North America is in the southeastern United States, its range extends into the northeastern and northcentral United States as well. The deciduous vines arise from massive perennial starchy root crowns, which can reach down to 4 m deep in the soil and weigh up to 136 kg. These massive roots provide energy for rapid initial growth in spring. Kudzu dies back to the ground after a hard freeze, but maximal growth rate in spring has been reported to be around 0.3 m per day and a plant may grow 20 to 30 m in a growing season. The fragrant purple flowers typically appear only on vines that are growing vertically on some support. Flowers occur on pseudoracemes, unusual inflorescences in which multiple flowers emerge from each bract axil.

Before Kudzu's invasive potential was recognized, it was repeatedly introduced into the southeastern United States for use as an ornamental and forage crop and for erosion control (Mitich 2000). Its subsequent rapid spread occurred despite conspicuously low seed set. Plants rarely flower before their third year and in some North American populations flowering is rarely if ever observed. In other areas, vines produce many flowers, but these often yield low numbers of seed pods or seed pods containing few seeds. In North America, many Kudzu populations sustain heavy losses to seed predators. Harvey (2009) documented the presence of extrafloral nectaries (EFNs) in Kudzu underneath the lateral floral peduncles. He speculated that documented herbivore-induced low seed set might result from a disruption of the protection normally afforded by ants attracted to EFNs. The atypical, near-monospecific stands of Kudzu in its introduced range may support a low diversity of ants or the ant species that typically visit Kudzu EFNs in its introduced range may not be as effective as those in its native range at finding or using the EFNs or are otherwise less effective as herbivore deterrents.

Kudzu is widely viewed as a seriously invasive plant in the United States, covering (often densely) over 1.2 to 2.8 million ha and this area has been estimated to be increasing on the order of 50,000 ha per year. Over time, Kudzu can cover large areas of potentially productive forest and farmland, resulting in estimated losses of $100 to 500 million per year. It is not yet clear what, if any, impact the recent arrival in the southeastern United States of the plataspid bug Megacopta cribraria (one of many herbivores feeding on Kudzu in Asia) may have on Kudzu (or other native and non-native hosts, including Soybean). If M. cribraria depletes Kudzu root reserves and reduces its ability to climb, this could benefit southern forests as well as farmers, utility companies, and railroads that must deal with Kudzu encroaching on their land, climbing utility poles, and growing across their tracks.

Kudzu is a common food crop in Java, Sumatra, and Malay, is well adapted to Puerto Rico, and grows in scattered parts of South America (Mitich 2000). Keung (2002) reviewed the entire genus Pueraria (which includes around 15 species).

(Mitich 2000 and references therein; Keung 2002; Harvey 2009 and references therein; Zhang et al. 2012 and references therein)

Kudzu was introduced into the U.S. in 1876 at the Philadelphia Centennial Exposition, where it was promoted as a forage crop and an ornamental plant. From 1935 to the mid-1950s, farmers in the south were encouraged to plant kudzu to reduce soil erosion, and Franklin D. Roosevelt's Civilian Conservation Corps planted it widely for many years. Kudzu was recognized as a pest weed by the U.S. Department of Agriculture and, in 1953, was removed from its list of permissible cover plants.

Kudzu was introduced to the United States from Japan in 1876 at the Philadelphia Centennial Exposition, as an ornamental plant. In early 1900s, it was recognized and promoted as a forage crop and planted throughout the southeastern U.S. In the 1930s and 1940s, the Soil Conservation Service paid southern farmers to plant kudzu to reduce soil erosion on deforested lands, resulting in over 1 million acres being planted. Kudzu, nicknamed “the vine that ate the South,” was recognized as a pest weed in the 1950s and removed from the list of acceptable species in the Agricultural Conservation Program. In 1998, it was listed as a federal noxious weed by the U.S. Congress.

More info for the term: cover

Kudzu originated in China and was brought to the United States from Japan in the late 1800s [34,66]. It is distributed throughout much of the eastern United States and is most common in the South. It occurs from Nebraska, Illinois, New York, and Massachusetts south to Florida and Texas. Kudzu also occurs in Hawaii [2,15,19,20,23,24,25,38,45,49,50,53,59]. Estimated kudzu cover in the Southeast is 7 million acres (2.8 million hectares), with the most extensive infestations in Mississippi, Alabama, and Georgia [51]. The Plants database provides a distributional map of kudzu.

Kudzu has periodically been reported in areas disjunct from the above description, but has not become established in any of these areas as of this writing (2002) [66]. It has recently been discovered near Portland, Oregon, and efforts to eradicate the population are underway [54].

The following biogeographic classification systems are presented as a guide to demonstrate where kudzu could potentially be found. Because the ecology of kudzu in North America has not been extensively studied, precise distribution information is lacking. Therefore these lists are somewhat speculative and may not be exhaustive or complete.

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This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

BLM PHYSIOGRAPHIC REGIONS [1]:

None

AL	AR	CT	DE	FL
GA	HI	IL	IN	KS
KY	LA	MD	MA	MS
MO	NE	NJ	NY	NC
OH	PA	SC	TN	TX
VA	WV	DC

Kudzu is common throughout most of the southeastern U.S. and has been found as far north as Pennsylvania.

Asia

Kudzu occurs primarily in the eastern U.S. and has been reported to be invasive in natural areas from Connecticut to Florida and west to Texas. Infestations have also been reported in North Dakota and Oregon. 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°F and annual rainfall is 40 inches or more.

Temperate and Tropical Asia, Australasia, and Pacific

Pueraria montana var. lobata (Willd.) Maesen & S.M. Almeida ex Sanjappa & Predeep:
Australia (Oceania)
China (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Pueraria thunbergiana Benth.:
Honduras (Mesoamerica)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Pueraria lobata (Willd.) Ohwi:
Canada (North America)
Japan (Asia)
Panama (Mesoamerica)
United States (North America)
Vietnam (Asia)
Caribbean (Caribbean)
China (Asia)
Thailand (Asia)
Philippines (Asia)
India (Asia)
Burma (Asia)
Laos (Asia)
Bhutan (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Distribution: Native of China and Japan sometimes cultivated in Murree hills.

More info for the terms: liana, root crown, tree, vine, vines

Kudzu is a climbing or trailing, herbaceous to semiwoody, nonnative, deciduous, perennial vine or liana. The compound leaves are 2 to 8 inches (5-20 cm) long [37,45]. Flowers are 0.8 to 1 inch (2-2.5 cm) long and are borne on 4- to 8-inch-long (10-20 cm) axillary racemes [37]. Seeds are produced in 1.6- to 2-inch (4-5 cm) long pods [37,45].

Kudzu exhibits a strong diurnal pattern in leaflet orientation, enabling plants to adjust the intensity of incident radiation upon exposed leaflets by altering their axial position relative to the sun. This trait results in comparatively reduced leaf temperatures and transpirational water loss during periods of intense mid-day summer sunlight, and may improve plant water-use efficiency [14,64]. This trait may also improve light penetration in kudzu-dominated tree canopies, enhancing the specie's ability to maintain high leaf areas. High leaf area in arboreal kudzu maximizes photosynthesis and enhances kudzu's ability to compete for light [64].

Kudzu accumulates and maintains substantial carbon reserves in large woody, tuberous roots. Roots can grow to 12 feet (3.6 meters) long in sandy soils and can weigh up to several hundred pounds [33]. Because of its large and deeply growing taproot, kudzu can withstand substantial periods of drought [66]. Deep roots also enable kudzu to maintain relatively high xylem water potentials throughout the hottest part of the day [64].

Kudzu is considered a semiwoody perennial because it exhibits 2 strategies for overwintering. The trailing, prostrate stems found in open areas die back to the root crown following the 1st frost. Stems that climb vertically, such as those invading a forest edge, often overwinter in the canopy. Overwintering vines develop thick bark, accumulate annual rings of vascular tissue, and can attain > 0.8-inch (2 cm) stem diameters [44,57]. North American kudzu apparently produces overwintering stems only on vigorous, climbing plants, but  in Japan kudzu produces overwintering stems even on prostrate plants [57].

Growth habit: Vines climb by twining the stem around a support such as the bole of a tree [6]. Spread of kudzu through forested areas may be accelerated by other vines such as Japanese honeysuckle (Lonicera japonica), since kudzu can more easily twine around smaller diameter vines than around bare tree trunks [33,35]. 

Kudzu ia a climbing, semi-woody, perennial vine in the pea family. Deciduous leaves are alternate and compound, with three broad leaflets up to 4 inches across. Leaflets may be entire or deeply 2-3 lobed with hairy margins. Individual flowers, about ½ inch long, are purple, highly fragrant and borne in long hanging clusters. Flowering occurs in late summer and is soon followed by production of brown, hairy, flattened, seed pods, each of which contains three to ten hard seeds.

• Plant: climbing perennial vine in the pea family (Fabaceae); vines may extend 32-100 ft. in length, with stems up to 4 in. in diameter; roots are fleshy, with massive tap roots that can get to 7 in. or more in diameter, 6 ft. or more in length, and weigh as much as 400 lbs.; up to 30 vines may grow from a single plant.
• Leaves: alternate, deciduous, and compound, with three broad leaflets up to 4 in. across, leaflets may be entire or lobed with hairy margins.
• Flowers, fruits and seeds: individual flowers, about ½ in. long, are purple, fragrant and borne in upright clusters during late summer; fruits are brown, hairy, flattened seed pods, each of which may contain as many as ten hard seeds.
• Spreads: expands locally by vegetative means through runners & rhizomes and by vines that root at the nodes to form new plants; may spread by seed in areas where a pollinator, the giant resin bee, occurs.
• Look-alikes: Thick tangles of various vines including grape, porcelainberry and bittersweet may be mistaken for kudzu as well as some native three-leaved vines in the pea family.

Perennial climber. Stem twining, setose. Stipules 10-12 mm long, free lateral, setose. Leaf pinnately trifoliolate, petiole 5-30 cm long, pilose. Stipels 8 mm long, setose, petiolule 5-8 mm long, pilose, lamina 7.5-21 cm long, 7.5-20.0 cm broad, broadly ovate to trilobed, tip acute, pubescent on both sides. Inflorescence an axillary, peduncled raceme, 15-32 cm long, velutinous, peduncle 2-3 cm long. Bracts c. 3 mm long, pilose to setose. Pedicel c. 7 mm long, pilose. Calyx 10-14 mm long, setose, teeth unequal, longest 7-12 mm long. Corolla purple with yellow spot at the base of the standard. Vexillum c. 15-18 cm long. Fruit c. 2.5-6.0 cm long, 7-8 mm broad, hispid, hairs brown.

More info for the term: climax

Kudzu is most invasive in the Southeast. Factors that determine occurrence
and invasiveness are most likely climate, light availability, and previous local
establishment. The particular local native plant community probably has little influence on
kudzu distribution and invasiveness. Even core areas of otherwise undisturbed,
insular forest habitat can eventually succumb, as invading kudzu slowly advances
from established populations along a forest perimeter. Any southeastern plant
communities in the vicinity of an existing kudzu population -- from pine plantations to mixed
hardwoods -- are likely to be at risk of
invasion.

Kudzu is not a climax dominant or indicator species in habitat type
classifications. However, due to its ability to achieve and maintain dominance on many
sites where it occurs, kudzu might be considered the de facto climax dominant on
these sites, regardless of site potential.

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This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):

More info for the terms: cover, fresh, hardwood, marsh

SRM (RANGELAND) COVER TYPES [47]:

601 Bluestem prairie

711 Bluestem-sacahuista prairie

726 Cordgrass

731 Cross timbers-Oklahoma

801 Savanna

802 Missouri prairie

803 Missouri glades

804 Tall fescue

805 Riparian

806 Gulf Coast salt marsh

807 Gulf Coast fresh marsh

808 Sand pine scrub

809 Mixed hardwood and pine

810 Longleaf pine-turkey oak hills

811 South Florida flatwoods

812 North Florida flatwoods

813 Cutthroat seeps

814 Cabbage palm flatwoods

815 Upland hardwood hammocks

817 Oak hammocks

818 Florida salt marsh

819 Freshwater marsh and ponds

821 Pitcher plant bogs

822 Slough

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This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

More info for the terms: cover, swamp

SAF COVER TYPES [12]:

17 Pin cherry

19 Gray birch-red maple

21 Eastern white pine

22 White pine-hemlock

23 Eastern hemlock

25 Sugar maple-beech-yellow birch

26 Sugar maple-basswood

27 Sugar maple

28 Black cherry-maple

33 Red spruce-balsam fir

37 Northern white-cedar

39 Black ash-American elm-red maple

40 Post oak-blackjack oak

42 Bur oak

43 Bear oak

44 Chestnut oak

45 Pitch pine

46 Eastern redcedar

50 Black locust

51 White pine-chestnut oak

52 White oak-black oak-northern red oak

53 White oak

55 Northern red oak

57 Yellow-poplar

58 Yellow-poplar-eastern hemlock

59 Yellow-poplar-white oak-northern red oak

60 Beech-sugar maple

61 River birch-sycamore

62 Silver maple-American elm

63 Cottonwood

64 Sassafras-persimmon

65 Pin oak-sweetgum

69 Sand pine

70 Longleaf pine

71 Longleaf pine-scrub oak

72 Southern scrub oak

73 Southern redcedar

74 Cabbage palmetto

75 Shortleaf pine

76 Shortleaf pine-oak

78 Virginia pine-oak

79 Virginia pine

80 Loblolly pine-shortleaf pine

81 Loblolly pine

82 Loblolly pine-hardwood

83 Longleaf pine-slash pine

84 Slash pine

85 Slash pine-hardwood

87 Sweetgum-yellow-poplar

88 Willow oak-water oak-diamondleaf (laurel) oak

89 Live oak

91 Swamp chestnut oak-cherrybark oak

92 Sweetgum-willow oak

93 Sugarberry-American elm-green ash

94 Sycamore-sweetgum-American elm

95 Black willow

96 Overcup oak-water hickory

97 Atlantic white-cedar

98 Pond pine

100 Pondcypress

101 Baldcypress

102 Baldcypress-tupelo

103 Water tupelo-swamp tupelo

104 Sweetbay-swamp tupelo-redbay

108 Red maple

109 Hawthorn

110 Black oak

111 South Florida slash pine

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This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

KUCHLER [27] PLANT ASSOCIATIONS:



K073 Northern cordgrass prairie

K074 Bluestem prairie

K077 Bluestem-sacahuista prairie

K078 Southern cordgrass prairie

K079 Palmetto prairie

K080 Marl everglades

K082 Mosaic of K074 and K100

K083 Cedar glades

K088 Fayette prairie

K089 Black Belt

K090 Live oak-sea oats

K100 Oak-hickory forest

K102 Beech-maple forest

K103 Mixed mesophytic forest

K104 Appalachian oak forest

K106 Northern hardwoods

K108 Northern hardwoods-spruce forest

K109 Transition between K104 and K106

K110 Northeastern oak-pine forest

K111 Oak-hickory-pine

K112 Southern mixed forest

K113 Southern floodplain forest

K114 Pocosin

K115 Sand pine scrub

Kudzu is typically found in open, disturbed areas such as abandoned fields, roadsides, and forest edges [14,61]. Spread is most rapid in open areas, and is slowed as kudzu encounters the shade of a forest edge [44]. Kudzu monocultures typically contain thousands of individual plants per acre [33].

Kudzu is most prolific in areas where winters are mild (40 to 60 degrees Fahrenheit (4-16 °C)), summer temperatures rise above 80 degrees Fahrenheit (27 °C), the growing season is long, and annual precipitation is > 40 inches (1,000 mm) [51,66]. Kudzu thrives in areas that experience abundant sunny weather during the growing season. Growth rates up to 3 times greater have been demonstrated on sunny days, compared to overcast conditions. Photosynthesis is not inhibited by high temperatures until 86 to 95 degrees Fahrenheit (30-35 °C) [64].

Kudzu grows on a variety of soil types [51,66], but performs best on deep, well-drained, loamy soils [61]. Because kudzu is a nitrogen-fixing plant, it is likely to be competitive on nitrogen-deficient sites [33].

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

ECOSYSTEMS [17]:

FRES12 Longleaf-slash pine

FRES13 Loblolly-shortleaf pine

FRES14 Oak-pine

FRES15 Oak-hickory

FRES16 Oak-gum-cypress

FRES17 Elm-ash-cottonwood

FRES18 Maple-beech-birch

FRES39 Prairie

FRES41 Wet grasslands

Kudzu grows well under a wide range of conditions and in most soil types. Preferred habitats are forest edges, abandoned fields, roadsides, and disturbed areas, where sunlight is abundant. Kudzu grows best where winters are mild, summer temperatures are above 80 degrees Farenheit, and annual rainfall is 40 inches or more.

More info for the terms: density, litter

Because fire may promote kudzu seed germination [33,39,55,56], managers should be aware of the potential for emergence of new plants following burning. Young kudzu plants are relatively easy to eradicate because they have not yet developed the extensive taproots of older plants. Miller [33] recommends burning after herbicide treatments to encourage germination of the kudzu seedbank, which can then be eliminated with a follow-up herbicide treatment. Burning as a follow-up to herbicide treatment can also bolster rapid recolonization of the site by native plants by removing litter and increasing light availability [61]. Dense kudzu litter remaining after herbicide treatments has been shown to inhibit germination of the residual native seedbank [43].

Burning may also be used to prepare sites for more efficient herbicide application, and to reveal size and density of root crowns previously hidden under dense litter [11,33]. Burning kudzu prior to other management activities can also reveal uneven terrain and other potential hazards previously hidden by dense mats of vegetation and litter [33].

More info for the term: surface fire

Because kudzu sprouts rapidly and vigorously after fire, questions
concerning susceptibility of foliage and stems to growing season fire may be
largely moot. Conditions likely to promote a surface fire of sufficient
severity to kill mature, well-developed root crowns, while theoretically
possible, have not been documented as of this writing (2002).

More info for the terms: ground fire, root crown

Kudzu sprouts from the root crown after fire. It quickly reestablishes following dormant-season fire, in some cases returning to previous levels of dominance by the 2nd postfire growing season [43,44].

There is speculation that the heat pulse from a ground fire may promote kudzu seed germination by increasing seedcoat permeability [33,39,55,56]. Laboratory experiments have demonstrated that seed dormancy may be broken by exposure to high temperatures, which promotes seedcoat scarification and allows permeability to water [55,56]. Information on postfire kudzu seedling establishment is lacking.

More info for the terms: competition, fuel, litter, top-kill

Green kudzu foliage probably does not burn well due to high water content. Growing season fire may top-kill kudzu foliage if enough combustible fuel is present to carry the burn [3]. Litter from vegetation that has recently succumbed to kudzu competition, especially persistent woody material, could provide substantial fuel. As of this writing (2002), there are no published descriptions of fire effects on kudzu.

More info for the term: vines

Dormant-season fire top-kills live, overwintering, canopy-draped vines [43], and can also kill root crowns of small, newly established plants [33].

More info for the terms: fire intensity, fuel, fuel loading, ladder fuels, litter, presence, severity, shrub

Fire adaptations: Kudzu escapes fire damage by maintaining perennating root crowns beneath the soil surface [43]. Kudzu stems and foliage are likely to resist fire damage during the growing season because they typically maintain high water content. Even during drought when nearby plants may be susceptible to fire due to desiccation, kudzu's deep taproot allows the plant to maintain a relatively high water content [64,66].

Soil heating as a result of fire may promote seed germination by scarifying the seedcoat, allowing water to penetrate into the seed [33,39,55,56]. In addition, dry kudzu litter can provide substantial fuel for dormant-season surface fires, perhaps providing a positive feedback in promoting seed germination. More research is needed to help understand the role of fire in promoting kudzu seed germination and postfire seedling establishment.

FIRE REGIMES: Because kudzu tends to be more opportunistic than predictable in its occurrence, it is difficult to ascribe particular FIRE REGIMES to it. To the extent that abundant, moist, green kudzu foliage can inhibit fire, kudzu may alter historic FIRE REGIMES by lengthening fire return intervals. Conversely, substantial fuel loading from dense mats of kudzu litter may enhance dormant-season fire potential. Additionally, the presence of kudzu in forest canopies may provide ladder fuels that enhance the likelihood of crown fires, particularly in areas where frequent surface fires may otherwise maintain seral pine or oak dominants. As kudzu invades shrub and forest communities, increases in standing and ground-layer fuels from dead woody plants that have succumbed to invasion could also increase fire intensity and severity. These scenarios are speculative. However, if kudzu continues as an important presence on the landscape, more research is need to determine how kudzu affects the fire ecology of native communities and ecosystems.

The following table lists fire return intervals for communities or ecosystems throughout North America where kudzu may occur. This list is meant as a guideline to illustrate historic FIRE REGIMES and is not to be interpreted as a strict description of FIRE REGIMES for kudzu.

Community or Ecosystem	Dominant Species	Fire Return Interval Range (years)
maple-beech-birch	Acer-Fagus-Betula	> 1000
silver maple-American elm	A. saccharinum-Ulmus americana
sugar maple	A. saccharum	> 1000
sugar maple-basswood	A. saccharum-Tilia americana	> 1000 [62]
bluestem prairie	Andropogon gerardii var. gerardii-Schizachyrium scoparium	26,41]
bluestem-Sacahuista prairie	A. littoralis-Spartina spartinae	41]
mangrove	Avicennia nitida-Rhizophora mangle	35-200 [40]
sugarberry-America elm-green ash	Celtis laevigata-Ulmus americana-Fraxinus pennsylvanica
Atlantic white-cedar	Chamaecyparis thyoides	35 to > 200 [62]
northern cordgrass prairie	Distichlis spicata-Spartina spp.	1-3 [41]
beech-sugar maple	Fagus spp.-Acer saccharum	> 1000
black ash	Fraxinus nigra
yellow-poplar	Liriodendron tulipifera	62]
Everglades	Mariscus jamaicensis
melaleuca	Melaleuca quinquenervia	40]
shortleaf pine	Pinus echinata	2-15
shortleaf pine-oak	P. echinata-Quercus spp.
slash pine	P. elliottii	3-8
slash pine-hardwood	P. elliottii-variable
sand pine	P. elliottii var. elliottii	25-45 [62]
South Florida slash pine	P. elliottii var. densa	1-5 [16,40]
longleaf-slash pine	P. palustris-P. elliottii	1-4 [40,62]
longleaf pine-scrub oak	P. palustris-Quercus spp.	6-10 [62]
pitch pine	P. rigida	6-25 [5,22]
pocosin	P. serotina	3-8
pond pine	P. serotina	3-8
eastern white pine	P. strobus	35-200
eastern white pine-eastern hemlock	P. strobus-Tsuga canadensis	35-200
eastern white pine-northern red oak-red maple	P. strobus-Quercus rubra-Acer rubrum	35-200
loblolly pine	P. taeda	3-8
loblolly-shortleaf pine	P. taeda-P. echinata	10 to
Virginia pine	P. virginiana	10 to
Virginia pine-oak	P. virginiana-Quercus spp.	10 to
sycamore-sweetgum-American elm	Platanus occidentalis-Liquidambar styraciflua-Ulmus americana	62]
eastern cottonwood	Populus deltoides	41]
black cherry-sugar maple	Prunus serotina-Acer saccharum	> 1000
oak-hickory	Quercus-Carya spp.
northeastern oak-pine	Quercus-Pinus spp.	10 to 62]
oak-gum-cypress	Quercus-Nyssa-spp.-Taxodium distichum	35 to > 200 [40]
southeastern oak-pine	Quercus-Pinus spp.
white oak-black oak-northern red oak	Q. alba-Q. velutina-Q. rubra
bear oak	Q. ilicifolia
bur oak	Q. macrocarpa	62]
oak savanna	Q. macrocarpa/Andropogon gerardii-Schizachyrium scoparium	2-14 [41,62]
chestnut oak	Q. prinus	3-8
northern red oak	Q. rubra	10 to
post oak-blackjack oak	Q. stellata-Q. marilandica
black oak	Q. velutina
live oak	Q. virginiana	10 to62]
cabbage palmetto-slash pine	Sabal palmetto-Pinus elliottii	40,62]
Fayette prairie	Schizachyrium scoparium-Buchloe dactyloides
southern cordgrass prairie	Spartina alterniflora	1-3 [41]
baldcypress	Taxodium distichum var. distichum	100 to > 300
pondcypress	T. distichum var. nutans	40]
eastern hemlock-yellow birch	Tsuga canadensis-Betula alleghaniensis	> 200 [62]
elm-ash-cottonwood	Ulmus-Fraxinus-Populus spp.	9,62]

More info on this topic.

More info for the term: vine

Kudzu is generally considered shade intolerant. A study at the University of Maryland showed that kudzu had the highest light requirement of 5 native and 3 exotic vine species of the Southeast, and establishment appears to be greatly inhibited under shaded, forest floor conditions [6]. While growth is slowed under shaded conditions, kudzu does have some ability to tolerate low irradiance levels [13,16]. This trait enables kudzu to maintain a competitively high leaf area index within a forest canopy, and to grow through several canopy layers before overtopping overstory trees [13].

Although kudzu is typically found in disturbed habitats, it can invade along edges of forested areas, enveloping, suppressing, and eventually killing mature trees. Kudzu monocultures can arrest successional development of native plant communities. Although kudzu has been established in North America for nearly a century, there are no published reports as of this writing (2002) that document long-term successional patterns in kudzu-dominated communities. Because kudzu spreads largely by asexual means in North America, populations are generally localized [44].

More info for the term: vines

Asexual regeneration: Kudzu commonly spreads by sending down roots from nearly every node along stems that contact soil. Rooting usually occurs every few feet along horizontal stems, and new root crowns develop at these nodes. New ramets develop the following spring, with new tendrils radiating in all directions from newly established root crowns [33,39,44].

Breeding system: No information

Pollination: No information

Seed production: Kudzu plants do not usually flower until their 3rd year [3]. Kudzu rarely flowers on prostrate vines and seeds are only produced on climbing vines [11,33,39]. Generally, a cluster of seedpods produces only 1 or 2 viable seeds [11]. Seed production is substantially limited in North America, especially in areas outside the Southeast [19,20,51].

Seed dispersal: No information

Seed banking: Seeds require scarification before they germinate. Although information on seed longevity is lacking, seed banks can apparently develop [11,33,39].

Germination: Seeds are unable to germinate until the seedcoats are rendered water permeable. Dormancy may be broken by physical scarification of seeds. Prolonged exposure to warm summer temperatures may promote germination by increasing seedcoat permeability, but detailed information is lacking [55,56].

Seedling establishment/growth: Kudzu reportedly sets seed infrequently in North America [51,66]. It is speculated that kudzu seedlings are far less competitive than asexually established ramets, and may be of minor concern regarding invasiveness [64]. The ecology of  kudzu sexual reproduction in North America is little studied and more research is needed in this area.

Vines can grow up to 1 foot (30 cm) per day and 33 to 99 feet (10-30 m) in a growing season [37,45]. 

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More info for the terms: chamaephyte, phanerophyte

RAUNKIAER [46] LIFE FORM:
Chamaephyte
Phanerophyte

More info for the term: vine

Vine

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Seasonal development varies with latitude and altitude. Leaf emergence occurs in late spring [13]. Shoot biomass and leaf area index peak near the end of June in the Georgia Piedmont. Stem elongation and leaf production are continuous throughout the growing season, but production varies with conditions [64]. Flowering occurs from late July through September, depending on location [13,14,37]. Seeds mature in fall [11,37,45]. Foliage is generally killed by the 1st fall frost, and plants are dormant until spring [66].

The spread of kudzu in the U.S. is currently limited to vegetative expansion by runners and rhizomes and by vines that root at the nodes to form new plants. Kudzu also spreads somewhat through seeds, which are contained in pods, and which mature in the fall. However, only one or two viable seeds are produced per cluster of pods and these hard-coated seeds may not germinate for several years.

The following is a representative barcode sequence, the centroid of all available sequences for this species.


No available public DNA sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 2
Specimens with Barcodes: 2
Species With Barcodes: 1

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 11
Species With Barcodes: 1

Kudzu is designated as a "noxious weed" in Kansas and Pennsylvania, and a "terrestrial noxious weed" in Florida. West Virginia classifies kudzu as "noxious weed but with crop value: permit may be issued for cultivation", and Oregon cites it as "noxious weed of known economic importance which occurs in small enough infestations to make eradication/containment possible; or is not known to occur, but is present in neighboring states" [60]. For more information see Invaders Database or Plants Database.

 
No special status

Rounded Global Status Rank: TNR - Not Yet Ranked

United States

Rounded National Status Rank: NNA - Not Applicable

More info for the terms: competition, cover, fire management, natural, root crown, tree, vines

Impacts: Kudzu invasion can have severe negative impacts on native plant communities. Because of its rapid growth rate and habit of growing over objects in its path, kudzu can outcompete native plants and quickly dominate habitats where it becomes established [61]. Kudzu infestations are typified by a continuous blanket of  monospecific foliage resulting in large-scale alteration of biotic communities [51]. Patches larger than 100 acres (40 ha) now exist in some areas of the South [36]. Plant densities in mature stands may be 1-2 plants per square foot or tens of thousands of plants per acre [11].

Spreading kudzu infestations can eliminate forest cover by enveloping trees along margins of wooded areas. Trees of any size may succumb to competition from arboreal kudzu vines, whose prodigious foliage reduces light availability within the canopy. Infested trees, especially shade-intolerant species such as native pines, are weakened from reduced carbon fixation. Additionally, the accumulation of several years' worth of vines draped within tree crowns provides enough downward tension that even large trees can be pulled to the ground. Once kudzu has gained access to the forest canopy, it is capable of spreading more quickly and aggressively throughout a contiguously forested area during subsequent growing seasons [33]. Presence of Japanese honeysuckle and other arboreal vines can exacerbate kudzu invasiveness. Because kudzu climbs by twining, it can ascend and spread into a forest canopy faster and more extensively by utilizing smaller-diameter vines rather than having to twine around larger-diameter tree boles [33,35].

Kudzu has been characterized as "perhaps the largest nonwoody weed problem in forest management in the South" [36]. Kudzu infestation can be costly to commercial timber producers by severely impacting productivity. While eradication treatments can be expensive, allowing kudzu to continue spreading only increases the acreage impacted and increases the difficulty (and expense) of eradicating older, denser, more intractable infestations [35].

Control: Because kudzu is so invasive, control is best equated with kudzu eradication [32,34]. To ensure complete eradication from a site and prevent reinvasion, every root crown must be killed [34]. Well-established stands may require as long as ten years to eradicate [61].

Kudzu eradication becomes increasingly difficult with increasing age of infestation [32,33,35]. Because kudzu develops large roots that store accumulated starch, older plants may be more resistant to control efforts and require more persistent or intensive management [33]. Vines that have spread vertically into tree canopies are thought to be more vigorous and to sequester starch reserves more rapidly and in greater quantity than prostrate-growing vines [11,33].

Weakening and eventual eradication of kudzu usually requires frequent defoliation by a single or several methods [11]. If managers are limited to a single defoliation treatment per year, it should be conducted in early fall (September in most areas). Kudzu allocates nearly all its resources to stem and foliar growth during the growing season, allocating few resources to root storage until near the end of the growing season. Kudzu recovers from defoliation by allocating root-stored resources to rapidly resume vigorous foliage growth. Defoliation activities conducted during the growing season can help deplete root energy stores and decrease plant vigor. However, fall defoliation is important to reduce resource allocation to roots, and hopefully gain substantial momentum toward eventual eradication [64].

For more information on kudzu control methods, see Mississippi State University Extension Service, Bugwood's Controlling Kudzu in CRP Stands, Controlling Kudzu in Western North Carolina, Southeast Exotic Pest Plant Council, Kudzu in Alabama, and the Virginia Natural Heritage Program websites.

Prevention: No information

Integrated management: No information

Physical/mechanical: Physical or mechanical methods that destroy kudzu foliage can weaken the plant by simultaneously limiting photosynthesis and depleting root-stored energy reserves. For these methods to be effective, especially when used alone, managers should be prepared to apply them persistently and frequently, often for several years. For old,  well-established stands, these methods are likely to be ineffective or require many years of intensive application. They are more likely to be effective when used in combination with herbicides.

The time required for eradication is a function of how long it takes to deplete root energy stores. Small, recently established patches (< 10 years old) can be eliminated by persistent weeding or mowing over a period of several (3-4) years [61]. Frequent mowing or cutting, ideally at 2-week intervals, weakens root crowns and inhibits photosynthesis [51]. Frequent mowing can be efficient and effective as long as all root crowns are in areas that are accessible [44].

Disking or cultivating infestations before and after chemical control efforts weakens plants and enhances herbicide effectiveness [33]. Cultivation may be inappropriate in natural areas or on steep or rocky terrain.

Individual plants may be hand pulled, but the entire root crown must be removed to prevent re-establishment [29]. Root systems of small, initial infestations can be excavated with a Pulaski or similar digging tool. All plant material should be removed from the site and destroyed by burning or bagging [51].

Fire: See Fire Management Considerations.

Biological: Intensive grazing can be an effective control measure, where appropriate. Young infestations (< 25 years old) are easier to control with grazing than older stands that have developed very large roots. Steady aboveground herbivory will gradually deplete root energy reserves, inhibit accumulation of new carbon stores by suppressing the amount of photosynthetic tissue, and prevent foliage from spreading into previously uninfested areas. Grazing kudzu infestations for 1 to 2 years prior to herbicide application can help to weaken plants, potentially making chemical control efforts more effective [33,34].

Chemical: Where appropriate, herbicides may be the most effective means of eradicating kudzu, whether used alone or in combination with other methods. Below is a list of herbicides that have been tested and judged effective for controlling kudzu in North America, as well as a brief discussion of important considerations regarding their use. This is not intended as an exhaustive review of chemical control methods. For more information regarding appropriate use of herbicides against invasive plant species in natural areas, see The Nature Conservancy's Weed Control Methods Handbook. For more information specific to herbicide use against kudzu, see Kudzu Eradication and Management, Bugwood's Controlling Kudzu in CRP Stands, Southeast Exotic Pest Plant Council, or the Kudzu in Alabama website.

Chemical	Considerations
picloram [8,10,32,35]	Perhaps the most (overall) effective chemical tested against kudzu [32,35,48]. Specific to broadleaf species; generally does not harm grasses [58]. May be mobile in soil solution and can leach into nearby surface water [31,58].
clopyralid [29,48]	More selective than picloram. Has little effect on members of the mustard family (Brassicaceae) and several other groups of broad-leaf plants, as well as grasses and other monocots. Chemically similar to picloram. Has a shorter half-life, but is more water soluble and has lower soil adsorption capacity [58].
fluroxypyr [48]
triclopyr [29,35,48]	Effective against arboreally established kudzu when applied to vines and foliage around the base of affected trees [35].
metsulfuron
hexazinone [29]
methyl 2- benzoate [10]
tebuthiuron
picloram + 2,4-D [32,35]
glyphosate [51,61]	Nonselective. "Cut-stump" method may be used to reduce mortality of neighboring native plants. For details see Southeast Exotic Pest Plant Council. Low toxicity to animals and relatively immobile in soil. Glyphosate itself may be the least potentially harmful of the above chemicals to the environment, although many surfactants or other adjuvants in some formulations are toxic [58].

Single applications of herbicides can reduce kudzu foliage by up to 2 orders of magnitude. However, continued spot treatment is usually required for several years for complete eradication due to recalcitrant root crowns and substantial root-sequestered carbon reserves that enable kudzu to resprout. Diligent monitoring and follow-up treatments may be required for 10 or more years on some sites [33,42]. Regrowth from surviving root crowns may often be delayed until 2 years after herbicide treatment, with no signs of survival during the 1st growing season. Several years of post-treatment monitoring and retreatment may be needed to ensure 100% mortality [33,48].

In general, herbicides are most effective against kudzu when applied after late May [32], although triclopyr was effective against tree-draped vines when applied in spring prior to the appearance of new growth [35]. Herbicides such as those listed above are likely to be most effective when applied near the end of the growing season when plants are translocating stem and foliar nutrients to root systems for dormant season storage [61]. Dormant-season herbicide application appears to be ineffective in controlling kudzu [48].

Higher herbicide application rates may be required for effective control on clayey or rocky soils or when infestations are older than 10 years [30,33,35]. Kudzu populations growing in a prostrate form, compared with plants growing vertically, are thought to be less vigorous and may be controlled using lower application rates [33,48].

Cultural: Planting grass in the fall following herbicide treatment has been recommended in order to stabilize soil and to provide competition against weakened kudzu plants and other weed species that may be present. Grasses are not injured by some herbicides that can kill kudzu (e.g., picloram or clopyralid) [33].

Planting competing vegetation that provides shade to treated sites, such as dense plantings of pine seedlings, can improve the effectiveness of repeated herbicide treatments [21], potentially reducing treatment duration.

Do not plant kudzu. The U.S. Department of Agriculture is investigating biological control agents for kudzu including the naturally occurring fungus Myrothecium verrucaria. 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 repeated cutting of vines just above ground level, frequent mowing and cultivation. Use of systemic herbicides with the active ingredients triclopyr and glyphosate have been used effectively.

These species are introduced in Switzerland.

More info for the term: cover

Kudzu has potential value as livestock forage [7,65]; however, it is easily overbrowsed, and its utility may not be sustainable [66]. Moreover, while it has been previously cultivated for livestock use and grazing can be an effective control measure (see Biological Control section below), kudzu has been identified as an invasive pest plant throughout the South. It is not recommended for cultivation for any purposes [11,51,61].

Kudzu seeds are a favored food for northern bobwhite, comprising 61.4% of the January and February diet of birds studied on an abandoned agricultural site in the Georgia Piedmont [28].

Palatability/nutritional value: Kudzu has comparable nutritional value to alfalfa (Medicago sativa) and Bermuda grass (Cynodon dactylon) hays. The following table provides information on nutritional value of kudzu [7]:

Parameters	Leaf	Stem	Root
Crude protein (% of dry matter)	17.5	10.3	8.6
Neutral-detergent Fiber (% of dry matter)	48.1	73.7	39.8
Acid-detergent Fiber (% of dry matter)	38.2	44.0	53.3
Ash (% of dry matter)	8.3	7.9	4.3
Ca (% of dry matter)	0.7	0.1	0.4
Fe (mg kg-1)	162.3	156.6	3,600
K (% of dry matter)	1.0	1.0	0.3
Mg (% of dry matter)	0.3	<0.1	0.1

Cover value: No information

Kudzu has potential value as livestock feed [7,65].

Kudzu kills or degrades other plants by smothering them under a solid blanket of leaves, by girdling woody stems and tree trunks, and by breaking branches or uprooting entire trees and shrubs through the sheer force of its weight. Once established, Kudzu plants grow rapidly, extending as much as 60 feet per season at a rate of about one foot per day. This vigorous vine may extend 32-100 feet in length, with stems ½-4 inches in diameter. Kudzu roots are fleshy, with massive tap roots 7 inches or more in diameter, 6 feet or more in length, and weighing as much as 400 pounds. As many as thirty vines may grow from a single root crown.

Its vigorous growth and large leaves smother and shade out native plants. It can kill trees through girdling and the extra weight of vines can lead to toppling during storms. Once established, kudzu plants grow rapidly, extending as much as 60 feet per season, about 1 foot per day.

In China the shoot is eaten after peeling; in Korea the stem is used for making ropes and a type of cloth.

Comments: The kudzu that is escaped widely in North America is called Pueraria lobata or Pueraria thunbergiana in most North American literature; Kartesz (1994 checklist) treats these plants as Pueraria montana var. lobata. No other varieties of Pueraria montana are reported from North America. LEM 3Jul95.