Kudzu (Pueraria lobata)
Kudzu is a vine with large leaves that can climb up to 30 m high or form very dense mats over the ground. It grows very quickly smothering and killing plants and damaging infrastructure.
Profile
How does this weed affect you?
Kudzu grows very quickly, up to 30 cm per day and it:
- smothers native plants, from ground covers to tall trees
- reduces food and habitat for native animals
- competes with horticultural crops and timber plantations
- restricts human and animal movement
- causes hazards because the dense mats can obscure ditches or drains
- grows over, and damages buildings, overhead wires and other infrastructure.
What does it look like?
Kudzu is a semi-woody perennial vine. It is deciduous in cool regions and during extended dry periods. Kudzu can climb up trees and over other structures up to 30 m high. It also can form extremely dense mats up to 2 m deep on the ground.
Leaves:
Leaves are alternate along the stem and are made up of three leaflets which are:
- dark green on top and light green to grey-green underneath
- 7–25 cm long and 5–13 cm wide
- usually lobed with 2 or 3 lobes
- oval to diamond shaped, if not lobed
- pointed at the tip
- sparsely hairy.
Flowers are:
- pea-like, arranged in a spike 10–25 cm long
- purple to pink with a yellow spot at the base
- individually 12–18 mm long
- grape-scented
- present in summer.
Seedpods are:
- brown with 3-10 seeds
- 5–9 cm long
- flattened and oblong shaped
- covered with reddish-brown hairs
Seed split on both sides when they release their seeds.
Stems are:
- up to 30 m long and 2.5 cm in diameter for the main stems
- up to 3 m long for secondary branches
- covered in grey to brown hairs.
Roots consist of:
- large edible tubers usually 60–90 cm long, (occasionally up to 1.8 m long) 15 cm in diameter and can weigh up to 180 kg.
- deep roots up to 5 m.
Similar looking plants
These plants look similar but they have smaller leaves that are not lobed and they do not have a yellow spot on the flowers:
- Lima bean (Phaseolus lunatus), which is commonly grown for the edible bean seeds.
- Hyacinth bean (Lablab purpureus), which is grown for food and has naturalised in NSW.
- Dipogon (Dipogon lignosus), an ornamental which has naturalised in NSW.
Where is it found?
Kudzu has been found in coastal regions of NSW, mostly on the North and Central Coasts.
It is native to south-east China and southern Japan. It may also be native to south-east Asia, Papua New Guinea and other Pacific islands but it is also possible that the plants were introduced to these countries as a food source. It was most likely introduced to Australia as a fodder crop and to limit erosion.
What type of environment does it grow in?
Kudzu can grow in a wide range of climates including tropical, subtropical and warm temperate regions. It grows best in areas with mild winters, hot summers (over 25°C), and an annual rainfall over 1000 mm. Although it is very sensitive to frost, frost-damaged plants can reshoot from tubers in spring. It can also tolerate dry periods by dropping its leaves.
It grows in many soil types and thrives in deep, loamy, well-drained soils. It does not grow well in waterlogged or highly alkaline soils.
Although kudzu is most vigorous in full sun, it can grow in partial shade. It often grows along waterways and in disturbed areas such as roadsides. In NSW it has also been found in open pastures, sclerophyll forests and subtropical rainforests.
Maps and records
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Recorded presence of Kudzu during property inspections (Map: Biosecurity Information System - Weeds, 2017-2023)
These records are made by authorised officers during property inspections under the Biosecurity Act 2015. Officers record the presence of priority weeds in their council area and provide this to the NSW Department of Primary Industries. Records reflect the presence of the weed on the date of inspection.
How does it spread?
Kudzu is mostly spread by people intentionally planting it for ornamental purposes, or for food for people and livestock.
By seed
Kudzu plants start producing seeds after three years. Seed viability is generally low, but occasionally some seeds remain viable for several years. Seeds can be spread by water, contaminated soil or contaminated fodder or mulch.
By plant parts
New plants can grow from stems and tubers and many vines can grow from one tuber. Contaminated soil moved by earth moving equipment can spread the tubers.
References
Csurhes, S. (2008). Invasive plant risk assessment: Pueraria montana var. Lobata. Department of Agriculture and Fisheries Biosecurity Queensland
Mitich, L. W. (2000). Kudzu [Pueraria lobata (Willd.) Ohwi] 1. Weed Technology, 14(1), 231-235.
Oakwood, M. (2021). Kudzu Management Plan Clarence, Coffs Harbour, Bellingen sub-region. NSW North CoastWeeds Advisory Committee.
PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 14 January 2022 from: https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Pueraria~lobata
Queensland, Department of Agriculture and Fisheries. (2020) Restricted Invasive Plant Factsheet: Kudzu Pueraria montana var. lobata . Retrieved 14 January 2022 from: https://www.daf.qld.gov.au/__data/assets/pdf_file/0003/49665/kudzu.pdf
Turnbull, I. and Storrie, A. (2004). Kudzu: Pueraria lobata. Identification and Control. Bellingen Shire Council.
More information
Control
By hand
If there are just a few small plants they can be removed by hand. Dig out the tubers and make sure all parts of the plant are removed and disposed of appropriately.
Disposal
Large amounts of kudzu can be composted on site if they are not in a flood zone. Piles should be checked regularly and any new growth should be treated.
Contact your local council for further advice on how to dispose of this plant.
Grazing
Continual grazing can weaken and kill kudzu. Pigs can dig out and eat the tubers.
Chemical control
Spot spraying
Thoroughly cover all of the foliage with the herbicide mix to the point of runoff.
For areas near waterways and native vegetation, apply herbicide to kudzu plants in full leaf, mid to late spring, followed by a second application in autumn.
In open pastures, apply a single application to kudzu plants in spring or autumn. Allow time for regrowth following grazing.
Herbicide options
WARNING - ALWAYS READ THE LABEL
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au
See Using herbicides for more information.
PERMIT 11604 Expires 30/09/2024
Metsulfuron-methyl 600 g/kg
(Various products)
Rate: 10 g per 100 L of water
Comments: Foliar application from spring to autumn. For further information read the permit critical use comments.
Withholding period: Nil (recommended not to graze for 7 days before treatment and for 7 days after treatment to allow adequate chemical uptake in target weeds).
Herbicide group: B, Inhibitors of acetolactate synthase (ALS inhibitors)
Resistance risk: High
PERMIT 11604 Expires 30/09/2024
Triclopyr 300 g/L + Picloram 100 g/L
(Various products)
Rate: 500 mL per 100 L of water
Comments: Foliar application from spring to autumn. For further information read the permit critical use comments.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate
Biosecurity duty
The content provided here is for information purposes only and is taken from the Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.
| Area | Duty |
|---|---|
| All of NSW | General Biosecurity Duty All pest plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable. |
| Greater Sydney |
Regional Recommended Measure* (for Regional Priority - Eradication)
Land managers should mitigate the risk of the plant being introduced to their land. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found. |
| Hunter |
Regional Recommended Measure* (for Regional Priority - Prevention)
Land managers should mitigate the risk of the plant being introduced to their land. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found. |
|
North Coast
Exclusion (eradication) zone: Clarence Valley LGA, Port Macquarie-Hastings LGA, Lord Howe Island. Core infestation (containment) zone: Ballina Shire LGA, Bellingen Shire LGA, Byron Shire LGA, Coffs Harbour City LGA, Kempsey Shire LGA, Kyogle Shire LGA, Lismore City LGA, Nambucca Valley LGA, Richmond Valley LGA, Tweed Shire LGA. |
Regional Recommended Measure* (for Regional Priority - Containment)
Whole of region: Land managers should mitigate the risk of the plant being introduced to their land. A person should not buy, sell, move, carry or release the plant into the environment. Exclusion zone: Notify local control authority if found. Land managers should eradicate the plant from the land and keep the land free of the plant. Core infestation: Land managers should mitigate spread of the plant from their land. Land managers should reduce the impact of the plant on assets of high economic, environmental and/or social value. |
| South East |
Regional Recommended Measure* (for Regional Priority - Eradication)
Land managers should mitigate the risk of the plant being introduced to their land. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found. |
| *To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfil the general biosecurity duty for this weed click here |
For technical advice and assistance with identification please contact your local council weeds officer.
Reviewed 2023
