What is it about?
In 2016 we completed the world’s largest Japanese knotweed field-trial after 5 years of research. We defined a new patent pending approach to Japanese knotweed treatment; The 4-Stage Model. This model links control method selection and application with the seasonal surface-rhizome flows in the knotweed plant.
Featured Image
Photo by Genevieve Perron-Migneron on Unsplash
Why is it important?
Seasonal targeting of Japanese knotweed treatment using the right control method provides more effective treatment outcomes, using lower doses of herbicide across the whole management life cycle. This means more affordable treatment, which is also more environmentally friendly than traditional blanket application of herbicides and ineffective application of carbon intensive physical control methods.
Perspectives
We began focusing on controlling Japanese knotweed at a time when there was a great deal of hysteria surrounding it, particularly in the UK. At the time, most information for people affected by the plant was largely based on anecdote. This led to the prospect of unscrupulous companies offering expensive and ineffective treatment options to homeowners. Additionally, large stakeholders were undertaking treatments that did not work, or worse, spread the plant further, creating greater problems and costing more money downstream. In short, it was quite incredible to us that there was no long-term, large-scale field trial analysis of the treatment methods used to control Japanese knotweed.
Dr Daniel Jones
Swansea University
Read the Original
This page is a summary of: Optimising physiochemical control of invasive Japanese knotweed, Biological Invasions, April 2018, Springer Science + Business Media, DOI: 10.1007/s10530-018-1684-5.
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Resources
BBC Wales News 28/08/2014 | Swansea University scientists trial knotweed killers
Swansea University scientists are conducting the largest field trial in Europe to find new ways of killing Japanese knotweed. The plant is one of the most damaging species in the UK and costs £8m a year to bring it under control in Wales.
BBC News 28/08/2014 | Swansea University scientists trial knotweed killers
Swansea University scientists are conducting the largest field trial in Europe to find new ways of killing Japanese knotweed. The plant is one of the most damaging species in the UK and costs £8m a year to bring it under control in Wales.
BBC News Science & Environment 28/08/2014 | Swansea University scientists trial knotweed killers
Swansea University scientists are conducting the largest field trial in Europe to find new ways of killing Japanese knotweed. The plant is one of the most damaging species in the UK and costs £8m a year to bring it under control in Wales.
ITV Wales News 01/10/2014 | Family finds house's value has halved after Japanese knotweed takes over garden
When you're selling a home, it's most people's biggest asset and you want it to look its best. But what if your garden has been over run with a destructive, invasive and almost impossible to eradicate weed?
BBC Wales News 02/08/2015 | Less hysteria needed to tackle Japanese knotweed
More co-ordination and less hysteria is what is required to tackle Wales' £8.8m-a-year Japanese knotweed problem, according to an expert. Swansea University's Dr Dan Jones said media scare stories could be discouraging homeowners from reporting and tackling infestations. He said a lack of planning and shrinking council budgets were also exacerbating the problem.
HorticultureWeek 09/09/2015 | Invasives conference to include sneak peek at Japanese knotweed field trials
Delegates at a conference about non-native invasive plants will be able to see first-hand pioneering field trials where control methods for Japanese knotweed are being researched. National trade body The Property Care Association (PCA) is holding its inaugural conference on invasive weeds on 23 September at The Vale Resort, Hensol, Cardiff. Before and after the conference, attendees will be able to visit large-scale field trials being conducted in South Wales by Swansea University researchers.
BBC Radio Wales, Eye on Wales 24/07/2016 | Japanese Knotweed
The investigative series looks at some of the science and stories behind the aggressive superweed Japanese knotweed, first found on the loose in Wales in the 1880s.
LAPU (Landscape & Amenity Product Update) 05/01/2017 | Twenty-one ways to tackle Japanese Knotweed
Dr Daniel Jones, lead researcher from the College of Science at Swansea University, is conducting one of the largest ever field trials to test ways of tackling Japanese knotweed, a group of invasive plants that are becoming more abundant in the UK.
Momentum 16/03/2018 | Swansea University Scientists Lead The Way In Tackling Japanese Knotweed
Following extensive trials, a team of bioscientists at Swansea University have developed an effective way to tackle Japanese knotweed, listed by the World Conservation Union as one of the world’s worst invasive species.
Swansea University 25/04/2018 | Swansea University scientists lead the way in tackling Japanese knotweed
Following extensive trials, a team of bioscientists at Swansea University have developed an effective way to tackle Japanese knotweed, listed by the World Conservation Union as one of the world’s worst invasive species, and an issue of huge concern to householders in the UK.
BBC Wales News 25/04/2018 | Japanese knotweed must be 'controlled and managed’
The infestation of Japanese knotweed must be "controlled and managed" after a five-year trial found the plant cannot be completely eradicated once it starts growing. Despite testing 19 different methods to try to control the growth of the plant, the Swansea University study did not find a way of completely removing it. Scott Rees, from Morriston, Swansea, said he may now have trouble selling his house because of knotweed in his garden, as banks could be unwilling to lend for a mortgage on the property.
BBC Wales News 25/04/2018 | Knotweed 'cannot be eradicated', Swansea Uni trial shows
The world's largest field trial on the control of Japanese knotweed, conducted in Wales, has found that eradicating the plant is not possible.
BBC Radio Wales 25/04/2018 | Good morning Wales
Interview about the journal article Optimising Physiochemical Control of Invasive Japanese Knotweed, including what the likely implications of the key findings will be.
BBC Wales Today 25/04/2018 | Coverage
News report about the journal article Optimising Physiochemical Control of Invasive Japanese Knotweed, including what the likely implications of the key findings will be.
BBC News at One 25/04/2018 | Coverage
News report about the journal article Optimising Physiochemical Control of Invasive Japanese Knotweed, including what the likely implications of the key findings will be.
The Conversation 25/04/2018 | We’ve found the best way to control Japanese knotweed
In the UK alone, it is estimated that controlling Japanese knotweed costs the economy around £170m every year. There are at least 15 different active control methods and herbicides used in the country, and an extensive control industry has built up around the plant. But, until now, there has never been a study of the scale needed to truly test how effective these treatments are.
Daily Mail 25/04/2018 | Japanese knotweed 'cannot be killed off': Scientists fail to destroy the invasive weed after 19 attempts
Homeowners have been warned there is no end to their worst garden nightmare - scientists have proved that the dreaded Japanese Knotweed cannot be killed off.
The Telegraph 25/04/2018 | Japanese knotweed cannot be cured, major study which tried 19 methods finds
Japanese knotweed cannot be cured, a major study which tried 19 methods over three years has found.
Wales Online 25/04/2018 | Japanese knotweed 'cannot be killed off' - scientists discover after trying for five years
Welsh scientists have spent five years on the world’s biggest study to test different ways of annihilating the invasive weed - but have come up empty handed.
Horticulture Week 25/04/2018 | Japanese knotweed can't be quickly eradicated by herbicides, argue consultants
Claims that Japanese knotweed can be eradicated in a short space of time using herbicides are misleading say Swansea University scientists behind Advanced Invasives, a south Wales-based consultancy tackling complex invasive plant species problems.
PHYS.ORG 25/04/2018 | Scientists lead the way in tackling Japanese knotweed
Following extensive trials, a team of bioscientists at Swansea University have developed an effective way to tackle Japanese knotweed, listed by the World Conservation Union as one of the world's worst invasive species, and an issue of huge concern to householders in the UK.
Brief Report 25/04/2018 | Experts try 19 ways to kill Japanese knotweed - and fail
A team of scientists has been trying for FIVE years to kill the invasive Japanese knotweed plant - but it has not managed it.
Long Room News 25/04/2018 | Experts try 19 ways to kill Japanese knotweed - and fail
Homeowners have been warned there is no end to their worst garden nightmare - scientists have proved that the dreaded Japanese Knotweed cannot be killed off.
Long Room News 25/04/2018 | Scientists lead the way in tackling Japanese knotweed
Following extensive trials, a team of bioscientists at Swansea University have developed an effective way to tackle Japanese knotweed, listed by the World Conservation Union as one of the world's worst invasive species, and an issue of huge concern to householders in the UK.
YAHOO! News 25/04/2018 | Japanese knotweed cannot be cured, major study which tried 19 methods finds
Japanese knotweed cannot be cured, a major study which tried 19 methods over three years has found. Researchers from Swansea University conducted the world's biggest ever study into eradicating the invasive weed at two sites in Taff's Well, near Cardiff, and in Swansea.
EurekaAlert! 25/04/2018 | Swansea University scientists lead the way in tackling Japanese knotweed
Following extensive trials, a team of bioscientists at Swansea University have developed an effective way to tackle Japanese knotweed, listed by the World Conservation Union as one of the world's worst invasive species, and an issue of huge concern to householders in the UK.
Derby Telegraph 26/04/2018 | Experts fail to kill Japanese knotweed after trying for five years
Scientists have failed to work out a way to kill the invasive Japanese knotweed plant - despite trying for FIVE years.
Essex Live 26/04/2018 | Homeowners warned destructive Japanese Knotweed 'cannot be killed off’
Scientists have failed to find a way annihilating the invasive weed.
Inside Conveyancing 26/04/2018 | Trade Body Support for New Research into Japanese Knotweed
Researchers from Swansea University have recently revealed their findings on how best to tackle the invasive, non-native plant.
Leicester Mercury 26/04/2018 | Experts try 19 ways to kill Japanese knotweed - and fail
A team of scientists has been trying for FIVE years to kill the invasive Japanese knotweed plant - but it has not managed it. But homeowners are being told not to panic if the plant has made its home on their land.
Narrowboat World 26/04/2018 | No way of killing Japanese Knotweed
Researchers from Swansea University conducted the world's biggest ever study over three years into eradicating the invasive weed at various sites and though 19 separate methods were used in an attempt to kill it, the plant survived them all.
Nottingham Post 26/04/2018 | Japanese knotweed can't be killed, say experts after trying for FIVE years
Advice on tackling nightmare invader Japanese knotweed has been released by a team of scientists who have been trying to kill the plant for five years. Even though they haven't managed to successfully kill the plant outright, they have offered advice on controlling it if it moves onto your patch.
Brief Report 26/04/2018 | Experts try 19 ways to kill Japanese knotweed - and fail
A team of scientists has been trying for FIVE years to kill the invasive Japanese knotweed plant - but it has not managed it.
BBC Breakfast 27/04/2018 | Interview
Interview about the journal article Optimising Physiochemical Control of Invasive Japanese Knotweed, including what the likely implications of the key findings will be. Regional BBC coverage of interview: London; Scotland; East Midlands; Radio Oxford; North East & Cumbria; Midlands; London; Manchester; Wales; Northern Ireland; South West; Yorkshire & Lincolnshire; South East; West; South.
BBC Wales News 28/04/2018 | Coverage
Coverage of the journal article Optimising Physiochemical Control of Invasive Japanese Knotweed, including what the likely implications of the key findings will be.
THIS IS LOCAL LONDON 29/04/2018 | Invasion of the Japanese knotweed
Japanese knotweed, as known by its Latin name ‘Fallopian japonica’, is weed grows and spreads rapidly and everywhere like wildfire, expect more greener and less fire…
News Shopper 29/04/2018 | Invasion of the Japanese knotweed
Japanese knotweed, as known by its Latin name ‘Fallopian japonica’, is weed grows and spreads rapidly and everywhere like wildfire, expect more greener and less fire…
Today’s Conveyancer 30/04/18 | New study finds Japanese Knotweed cannot be cured
Recent research has found that the infamously invasive Japanese Knotweed cannot be cured. Following a study conducted by Swansea University into the destruction of the plant, scientists found no definite ways of killing it completely using methods currently available.
Inside Conveyancing 30/04/2018 | Swansea University Japanese Knotweed Trials Do Not Tell The Full Story
New research released this week by Swansea University’s Professor Dan Eastwood and Dr Dan Jones, has called into question the claim that Japanese Knotweed can be eradicated.
Myerson 30/04/2018 | Don’t let Japanese Knotweed be a thorn in your side
Researchers at Swansea University have carried out a three year study into the eradication of Japanese Knotweed.
BBC Radio 2 30/04/2018 | Coverage
Coverage of the journal article Optimising Physiochemical Control of Invasive Japanese Knotweed, including what the likely implications of the key findings will be.
Pro Landscaper 01/05/2018 | Japanese knotweed (page 96)
Dr Dan Jones tells Pro Landscaper about his extensive research into Japanese knotweed (page 96).
Today’s Conveyancer 01/05/2018 | Japanese knotweed research does not tell full story says removal specialist
Recent research suggesting that Japanese Knotweed is incurable has come into question by a company specialising in the removal of the plant.
HorticultureWeek 02/05/2019 | Trade bodies welcome research into Japanese knotweed eradication
The new research, from Swansea University, found claims that Japanese knotweed can be eradicated in a short space of time using herbicides are misleading.
Inside Conveyancing 02/05/2018 | INNSA Welcomes the New Research Produced by Swansea University
INNSA welcomes the new research produced by Swansea University which re-iterates the information provided within the INNSA Code of Practice for Managing Japanese Knotweed produced in April 2017.
LEXOLOGY 02/05/2018 | "Japanese Knotweed Cannot be Eradicated" - Allegedly
A number of media sources, including the BBC, have made such claims in the last week. They have based this upon a paper published online on 23 April 2018 by the Department of Biosciences at Swansea University. However, that conclusion is not stated in the research paper.
Business News Wales 04/05/2018 | Swansea University Scientists Lead the Way in Tackling Japanese Knotweed
Following extensive trials, a team of bioscientists at Swansea University have developed an effective way to tackle Japanese knotweed, listed by the World Conservation Union as one of the world’s worst invasive species, and an issue of huge concern to householders in the UK.
earth.com 04/05/2018 | One of the world’s most invasive species cannot be killed
The invasion of Japanese knotweed is challenging scientists who are testing for ways to get the species under control. Experts from Swansea University conducted the largest-ever field study to find a ways to kill the aggressive plant, and have 19 failed approaches to show for it
BBC WM 05/05/2018 | Coverage
Coverage of the journal article Optimising Physiochemical Control of Invasive Japanese Knotweed, including what the likely implications of the key findings will be.
The Telegraph 07/05/2018 | Three unexpected ways your home purchase could fall through
Property ownership remains the dream for most Britons, but for the majority of would-be buyers it’s far from plain sailing.
MORTGAGE STRATEGY 14/05/2018 | Market Watch: The crawl of the invertebrates
Finally, a headline no one wanted to see. According to boffins at Swansea University, everyone’s favourite plant and the scourge of mortgage applications everywhere, Japanese Knotweed, cannot be eradicated. Not. Ever.
Guardian 15/05/2018 | Plantwatch: glyphosate is only way to manage Japanese knotweed
Japanese knotweed is said to cost UK economy £170m a year, but so far only solution is controversial glyphosate-based herbicide.
BBC Radio Cornwall 02/06/2018 | Coverage
Coverage of the journal article Optimising Physiochemical Control of Invasive Japanese Knotweed, including what the likely implications of the key findings will be.
BBC Rip Off Britain 18/06/2018 | Interview
Angela Rippon, Gloria Hunniford and Julia Somerville expose the car-cloning scam that led to armed police turning up on one startled viewer's doorstep. Also, the new build home owners who fear a plant has knocked thousands of pounds off the value of their properties, and the former police officer left seriously out of pocket after a purchase that was not what it seemed. Plus more advice at the annual Rip Off Britain pop-up shop.
The Times 28/06/2018 | How can landowners untangle the problem of Japanese knotweed?
Japanese knotweed is a growing problem invading the property industry. The species is notoriously difficult to remove. In fact, academics at Swansea University concluded in April that there was no way of eradicating it.
Sava Technical Bulletin For Residential Surveyors Issue 29 (July 2018) | Japanese Knotweed - Understanding The Plant (p22)
Dr Dan Jones summarises the research conducted by Swansea University into Japanese knotweed.
24 housing 09/07/2018 | Trade association sets the platform for debate around new Japanese knotweed findings
A national trade body says a new study into Japanese knotweed reinforces the fact the invasive weed’s impact on property is at odds with its reputation in the UK.
FM Industry 10/07/2018 | Trade Association Sets Stage for Japanese knotweed Debate
Discussion around new research focussing on Japanese knotweed. Includes comment on research conducted at Swansea University by Dr Dan Jones.
PRESSONE 11/07/2018 | Lulişca invadatoarea
Japanese knotweed is found throughout Romania and is becoming particularly problematic in Sighisoara - a UNESCO World Heritage site. Dr Dan Jones discusses how research conducted by Swansea University can be used for the control of knotweed in these, and other areas of Romania.
Inside Conveyancing 11/07/2018 | Trade Association Sets the Platform for Debate Around New Japanese Knotweed Findings
Discussion around new research focussing on Japanese knotweed. Includes comment on research conducted at Swansea University by Dr Dan Jones.
BBC Wales News 16/07/2018 | Coverage
Coverage of the journal article Optimising Physiochemical Control of Invasive Japanese Knotweed, including what the likely implications of the key findings will be.
Advances Magazine 20/07/2018 | Investigating treatments for an invasive plant species (p10)
In 2018, Swansea-based company Advanced Invasives completed the world’s largest field trial on Japanese knotweed, in partnership with Swansea University’s Department of Biosciences. The seven-year research project involved three years of experiments testing the main physical and chemical methods of controlling Japanese knotweed used in the UK.
HOME DESIGNER & ARCHITECT 23/07/18 | Successful Control or Eradication of Japanese Knotweed
The last few months have seen some interesting news and events regarding Japanese knotweed.
BALI Hub (British Association of Landscape Industries) 25/07/18 | Japanese Knotweed - Fall from Grace
Overview of historical, ecological and technical control elements of Dr Dan Jones' 7 year Japanese knotweed research programme.
ProLandscaper 01/10/2018 | Roundup of Invasives Science Live
The Invasives Research Centre (IRC), the original field trial site used by Dr Dan Jones for his PhD studies, hosted a specialist invasive plants workshop 'Invasives Science Live', sponsored by ICL, Green-Tech, Complete Weed Control and Advanced Invasives.
House of Commons 22/01/2019 | Science & Technology Committee Inquiry: Japanese Knotweed and the built environment
House of Commons Science & Technology Committee Inquiry: Japanese Knotweed and the built environment. One-off oral evidence session with relevant experts, specifically to explore the science behind the effects of Japanese Knotweed on the built environment.
Mail Online 23/01/2019 | Bureaucrat jargon is spreading like knotweed across the UK: QUENTIN LETTS on yesterday in Parliament
Interesting take on the House of Commons Science & Technology Committee Inquiry!
House of Commons 22/01/2019 | Science & Technology Committee Inquiry: Japanese Knotweed and the built environment
The Science and Technology Committee held a one-off oral evidence session in early 2019 with relevant experts, specifically to explore the science behind the effects of Japanese Knotweed on the built environment.
The ENDS Report 23/01/19 | Risk from Japanese knotweed overplayed, experts argue
The risk of damage from Japanese knotweed is being overplayed by mortgage lenders, according to experts giving evidence to a House of Commons committee.
The Slate 08/05/2019 | Oh, No, Not Knotweed!
It grows rapidly. It’s nearly impossible to kill. It’s terrorized England. And now it’s all over my American backyard.
House of Commons 16/05/2019 | Report - Science & Technology Committee Inquiry: Japanese Knotweed and the built environment
The Science and Technology Committee has concluded that the current approach to Japanese knotweed is ‘overly cautious’ and more academic research is needed into its effects in the built environment.
The ENDS Report 16/05/19 | Why MPs believe the Japanese knotweed threat is being overplayed
An inquiry has found that the effects of Japanese knotweed have been exaggerated and are unduly hindering property sales and undermining their value.
Sava Technical Bulletin For Residential Surveyors Issue 32 (August 2019) | Japanese Knotweed - Where Are We Now? (p8)
Japanese knotweed has a demonstrable impact on the built environment and the native ecology and environment of the UK. Following the House of Commons Science and Technology Committee report, this article takes stock of where we are and how our approach to knotweed may change in the future.
Lets Science That! 11/07/2020 | Why is evidence-based research important?
Interviewed with Leena Alzafarani in New York for Let's Science That! We discussed why evidence-based answers to tricky scientific questions are really important!
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