Fallopia japonica (Japanese Knotweed)

This page provides links to guidance documents that have been produced by a range of organisations.  While this information should be a useful resource, the Non-native Species Secretariat cannot endorse any guidance.  Details of the Japanese Knotweed code of practice, produced by the Environment Agency in England, are provided below, followed by a list of other resources that are available.  If you would like to recommend management information to include here please contact us

Japanese Knotweed Code of Practice

The Environment Agency in England has developed a code of practice to help developers manage Japanese knotweed legally. It also gives options for cost effectively managing Japanese knotweed on site. Hauliers, architects, planners, designers, contractors, consultants and landscape gardeners can also use this code.

Link to the Environment Agency's Japanese Knotweed Code of Practice

The code of practice is intended to reduce waste and regulation. It is not intended as comprehensive guidance on control methods, but it does describe a number of methods that have been proven to be effective. Whatever method you use to treat soil contaminated with Japanese knotweed rhizome on site, you must follow the guidance in Section 2.4 with regards its reuse on site. If it is taken off-site it must be disposed of via landfill or incineration. It should not be sold or disposed of as soil.

You do not need to be a specialist contractor to administer the code of practice, but there are a number of companies that specialise in Japanese knotweed treatment. Many, but not all, of these companies belong to one of two trades’ bodies that specialise in the management of invasive non-native plants in general, and Japanese knotweed in particular.



The Environment Agency cannot endorse any company offering these services, and you must ensure that they either operate within the code of practice, or obtain the necessary environmental permits for their activities.

You can get advice on managing waste in England from the Environment Agency on their customer services line; 03708 506 506

If you see anyone illegally moving or disposing of waste, call the incident hotline on; 0800 80 70 60.

Additional resources

Japanese knotweed - Gov.UK web pages

Japanese knotweed: controlling it on your land | Welsh language version - Welsh Government (2020)

Japanse knotweed advice: community and voluntary groups | Welsh language version - Welsh Government (2020)

Optimising physiochemical control of invasive Japanese knotweed. Jones et al 2018.  Biological Invasions.

The Control of Japanese Knotweed (Fallopia japonica) in Construction and Landscape Contracts. Model Specification and Guide to Procurement - Welsh Government (2011)

On-site management of Japanese Knotweed and associated contaminated soils - SEPA Technical Guidance Note. Scottish Environment Protection Agency (2008)

Managing invasive non-native plants in or near fresh water - Environment Agency 2010

Kabat, T.J., Stewart, G.B., and Pullin, A.S. (2006). Are Japanese knotweed (Fallopia japonica) control and eradication interventions effective? Systematic Review No. 21. Centre for Evidence-Based Conservation, Birmingham, UK.

Invasive Alien Species Fact Sheet: Fallopia japonica - NOBANIS (downloaded from website March 2014)

Invasive Species Compendium: Fallopia japonica (Japanese knotweed) - CABI website (March 2014)

Information Sheet 5: Japanese Knotweed - Centre for Ecology & Hydrology (CEH 2004)

Kelly, J., Maguire, C.M. and Cosgrove, P.J. (2008). Best Practice Management Guidelines Japanese knotweed Fallopia japonica. Prepared for NIEA and NPWS as part of Invasive Species Ireland.

Japanese Knotweed Guidance for Identification & Control - Cornwall Knotweed Forum

Kabat, T.J., Stewart, G.B., and Pullin, A.S. (2006). Are Japanese knotweed (Fallopia japonica) control and eradication interventions effective? Systematic Review No. 21. Collaboration for Environmental Evidence

Japanese knotweed - Fallopia japonica. Angling Trust

Japanese Knotweed - Invasive Species Ireland (downloaded from website March 2014)

Japanese Knotweed: Control of Knotweed - Devon County Council website (March 2014)

Delbart, E., Mahy, G., Weickmans, B., Henriet, F., Crémer, S., Pieret, N., Vanderhoeven,, S. & Monty, A. (2012) Can Land Managers Control Japanese Knotweed? Lessons from Control Tests in Belgium. Environmental Management, 50(6): 1089-1097

Djeddour, D. H. & Shaw, R. H. (2010) The Biological Control of Fallopia Japonica in Great Britain: Review and Current Status. Outlooks on Pest Management, 21(1): 15-18(4)

Beerlin, D.J. (2006) The use of non-persistent herbicides, glyphosate, and 2,4-D amine, to control riparian stands of Japanese knotweed (reynoutria japonica houtt.). Regulated Rivers: Research & Management, 5(5): 413-417

Ford, S. (2004) Cut and inject herbicide control of Japanese knotweed Fallopia japonica in Cornwall, England.  Conservation Evidence, 1: 3-5

Best Management Practices: Invasive Knotweeds. King County Noxious Weed Control Program (2008)

Knotweed Action Group website www.knotweedactiongroup.com

Good practice management guidance for Japanese knotweed - RAPID LIFE (2018)

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