Kudzu (Pueraria montana)

Synonyms: Pueraria lobata, Pueraria montana var. lobata, Pueraria thunbergiana, Dolichos lobatus

Common Names: Kudzu vine, Japanese arrowroot, foot-a-night vine, the plant that ate the South

Description:

Kudzu (Pueraria montana) is a fast-growing climbing vine from eastern Asia that smothers everything in its path, earning it the nickname "the plant that ate the South" [1][4]. It was brought to the United States in 1876 and later planted widely across the Southeast to control erosion, before it spread out of control [4]. MISIN tracks it because a single patch can grow up to a foot a day, blanketing and killing trees, shrubs, and native plants under a dense mat of leaves [3][4].

Habit:

Kudzu is a sprawling, woody vine that climbs over and drapes across anything nearby ? other plants, fences, telephone poles, even whole trees [4]. Its stems are hairy and can stretch up to 100 feet long, rooting wherever a stem joint touches the ground so the patch keeps widening [2][4]. The leaves are the easiest clue: each one is made of three broad leaflets, often with shallow lobes and a covering of fine hairs, and each leaflet ends in a long narrow point [4]. In late summer the vine produces upright clusters of pea-like, reddish-purple flowers that smell like grapes, followed by flat, hairy brown seed pods [2][4].

Kudzu is easiest to spot from midsummer into fall. Look for the grape-scented purple flower spikes in August and September, and for the unmistakable curtains of leaves smothering trees and roadside banks through the growing season [4]. After the first frost the leaves die back to brown, but the thick, woody root crowns and giant underground tubers survive the winter and resprout in spring [4].

At-a-glance cues:

1. Leaves with three broad, hairy leaflets, each ending in a long narrow point [4]
2. Hairy vines up to 100 feet long that root at the joints and climb over everything [2][4]
3. Upright clusters of reddish-purple, grape-scented flowers in late summer [2][4]
4. Dense mats of foliage smothering trees, fences, and roadside banks [4]

Leaves:

1. Arrangement: alternate along the stem [4]
2. Type: compound with three leaflets (trifoliate) [4]
3. Shape: broad leaflets, often with two or three shallow lobes, each leaflet tipped with a long narrow point [4]
4. Size: leaflets large, up to about 10 inches (25 cm) long [4]
5. Surface: covered with fine hairs on both the leaflets and the leaf stalks [4]

Stems:

1. Habit: trailing and climbing vine, woody at the base and herbaceous toward the tips [4]
2. Length: stems up to 100 feet long in a single season [2][4]
3. Surface: covered with golden-brown hairs, especially when young [4]
4. Rooting: stems root at the joints (nodes) where they touch soil, forming new plant crowns [2][4]
5. Roots: a massive system anchored by large underground tubers that can grow very heavy and several feet deep [4]

Flowers:

1. Color: reddish-purple to lavender [2][4]
2. Shape: pea-like, typical of the bean family [2]
3. Arrangement: in upright elongated clusters (racemes) rising from the leaf joints [4]
4. Scent: strongly fragrant, often described as smelling like grapes [4]
5. Bloom time: late summer, mainly August into September [4]

Fruit and seeds:

1. Fruit: a flat, dry bean pod covered in golden-brown hairs [4]
2. Seeds: a few hard seeds per pod; only a portion are viable [2][4]
3. Ripening: pods mature in fall [4]
4. Spread: most new growth comes from stems rooting at the joints rather than from seed [2][4]

Habitat:

Kudzu grows best in open, sunny places with mild winters. Look for it along forest edges, roadsides, railroad banks, abandoned fields, and other disturbed ground [2][4]. It thrives in full sun and well-drained soil and climbs toward the light, so it is especially common where a forest meets a clearing [4]. It does not tolerate repeated mowing or regular cultivation, which is one key to controlling it [2].

Kudzu is native to eastern Asia [1]. In North America it is an introduced invasive, most widespread across the southeastern United States, where it covers large areas, and it continues to push northward into new regions [3][4].

Reproduction:

Kudzu spreads mostly by creeping, not by seed. Its long stems run along the ground and take root wherever a joint touches soil, and each new rooted point becomes a fresh plant crown [2][4]. This is how a single patch widens relentlessly, and it is also how kudzu hitches a ride to new ground ? a piece of rooted stem or root crown moved in fill dirt, on equipment, or in dumped yard waste can start a whole new infestation [4]. The plant also makes seed in its hairy pods, but only some of those seeds sprout, so spread by seed is slower and less common than spread by runners [2][4].

For control, the timing that matters is simple: the plant pours its energy into a deep, woody root crown and large underground tubers that store reserves and resprout each spring [4]. Cutting or mowing repeatedly through the growing season drains those reserves over time, and removing the root crowns is what finally kills a plant [2][4].

Impact and Damage:

For a homeowner, kudzu is a property problem before it is anything else. It grows up to a foot a day in summer and will climb and bury sheds, fences, gardens, and trees, and its weight can break branches and pull down limbs [3][4]. It also climbs power poles and structures, where it creates a maintenance headache and a safety hazard [4]. Kudzu is not poisonous to touch, but its sheer speed and bulk make it hard to live with once it takes hold [4].

In natural areas, kudzu is one of the most damaging invasive vines in North America [3]. It forms dense blankets that block sunlight and smother and kill native shrubs and trees, sharply reducing the variety of plants and the wildlife that depend on them [3][4]. As a member of the bean family, it also adds nitrogen to the soil, which can change soil chemistry in ways that favor more weeds over native plants [3]. These impacts, combined with the high cost of controlling it on forests, roadsides, and utility lines, make kudzu a major economic and ecological threat [3].

Similar species:

Poison ivy (Toxicodendron radicans) also has leaves made of three leaflets and can climb, so it is easily mistaken for young kudzu. You can tell them apart because poison ivy lacks the fine hairs along the leaflet edges and stems that kudzu has ? but if you are unsure, do not handle it, since poison ivy causes a skin rash.

Virgin's bower (Clematis virginiana) is a native climbing vine with leaves of three leaflets as well, but its leaflets are toothed along the edges and are not hairy like kudzu's.

American hog-peanut (Amphicarpaea bracteata) is a native vine in the bean family that closely resembles kudzu with its three leaflets, but it is far less hairy and its leaflets lack the long narrow point found on kudzu's leaflet tips.

Monitoring and rapid response:

Signs to watch for:

1. Hairy vines with three-leaflet leaves climbing over plants, fences, or trees, most obvious through the growing season [4]
2. Upright clusters of reddish-purple, grape-scented flowers in August and September [4]
3. Dense curtains of foliage smothering roadside banks, forest edges, or trees [3][4]

What you can do:

1. For small or young patches, dig out the woody root crowns ? the knobby bases where the vines emerge from the ground ? since removing every crown is what finally kills the plant [2][4].
2. Cut or mow the vines repeatedly through the growing season, year after year, to starve the roots; a single cutting will not work because the plant resprouts from its reserves [2][4].
3. Bag and dispose of rooted stem pieces and root crowns rather than composting them or moving them in yard waste, which can start a new patch [4].
4. Do not move fill dirt or equipment from an infested area without cleaning off soil and plant fragments first [4].
5. Natural area crews should map and clear small outlying patches first to stop the spread, then work back toward the core, repeating cutting and crown removal across the site over several years [4].

When to call a professional:

1. Large, established stands, vines on power poles or structures, or steep banks and rights-of-way where hand removal is impractical or unsafe [4].
2. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. USDA National Invasive Species Information Center. Kudzu. invasivespeciesinfo.gov
2. University of Maryland Extension. Kudzu. extension.umd.edu
3. Forseth IN, Innis AF (2004). "Kudzu (Pueraria montana): History, Physiology, and Ecology Combine to Make a Major Ecosystem Threat." Critical Reviews in Plant Sciences 23(5):401?413. semanticscholar.org
4. Southeast Exotic Pest Plant Council. Kudzu, Pueraria montana ? Invasive Plant Manual. se-eppc.org

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