All the latest news and latest sector information from INNSA, our members and partners.

To sign up to receive the latest newsletter click here.

Invasive & Injurious Weeds Module

Wednesday, 02 May 2018 10:58

INNSA Welcomes New Research


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.

The key messages from the research match those of the INNSA membership, all of whom have signed up to the Invasives Code. It highlights the need to use contractors who apply the correct herbicide at the right time of year to get maximum effect and for this to be independently vetted.

INNSA and its members have always promoted the need for a sustained program when treating invasive weeds as herbicides are not an instant solution. The control of invasive plants with herbicides needs careful planning, knowledge and experience, and can then be highly efficient and effective. Along with insurance backed warranties, customers can have peace of mind that the plant will be successfully controlled and over time eradicated.

James Sherwood-Rogers the Chairman of INNSA commented ‘INNSA is all about setting standards for the invasives remediation industry and our Code of Practice for Managing Japanese knotweed is the authoritative document on the effective treatment of this very difficult species. All of our members work to the demanding standards that it sets and are also members of the Amenity assured scheme’

Invasives Code subscriber appointed following Court Case

Owner who allowed Japanese knotweed to spread found liable for all costs

In a landmark court case, a property owner who allowed Japanese knotweed to spread across her property to the extent that it put the value of an adjoining property at risk, was ordered by the County Court in Truro to employ Cornwall Council’s contractor, Cormac Solutions Limited, to implement a programme of remediation that may take 5 years.

The property owner was also required to pay substantial but undisclosed court costs. The case, which bears resemblance to a similar case against Network Rail in Wales, may set a precedent for those people who have knotweed on their land and allow it to spread to the extent that it puts adjoining property values at risk.

Cormac Solutions, who have been appointed to eradicate the infestation, are subscribers to the Invasives Code which sets high quality standards for invasive species remediators and are also a member of the Invasive Non-Native Specialists Association (INNSA) the only industry specific trade body that represents companies that adhere to the highest technical industry standards.

Tim Bird from Cormac Solutions Limited said ‘we are very pleased to have been appointed to eradicate the knotweed infestation in Maenporth as a result of the Court decision. It is important when appointing a contractor to remediate an infestation that you can have peace of mind as to the quality of work and that the contractor will be around for the long term. As a subscriber to the Invasives Code and a member of INNSA, which requires very high technical standards of its members as laid out in the INNSA Code of Practice for Managing Japanese knotweed, our customers can have that peace of mind.’

James Sherwood-Rogers, the Chairman of INNSA said ‘we believe that the Court decision sends a clear message that it is important to select a remediator that subscribers to the Invasives Code and follows the INNSA Code of Practice for Managing Japanese knotweed. As remediation programmes can take 5 years or more, it is vital that property owners can depend on the contractor that they choose to work for them.’

More information about the Invasives Code can be found at 


Thursday, 01 February 2018 10:38

INNSA Annual Conference 2018

Show of resilience from invasives experts at industry conference

The Invasive Non-Native Species Association (INNSA) hosted its fourth annual conference in Derby in the wake of a turbulent last year for remediation professionals.

INNSA 2018 brought together experts from a range of sectors affected by invasive species, including property, amenities, remediation and legal, to provide updates on the previous year and future advice for those at risk of infestations of the likes of Japanese knotweed.

2017 was a challenging year for the invasives industry, with months of uncertainty on the renewal of Glyphosate licensing causing fears of food shortages and harmful non-native infestations growing out of control. It also saw a landmark ruling against National Rail for failing to control Japanese knotweed, and worrying new research conducted by the Crop Protection Association (CPA) revealed that one in seven homeowners saw a property deal fall through due to a knotweed infestation. One in four stated they knew nothing at all about the invasive plant, demonstrating more still needs to be done to educate the general public.

The theme of this conference was reducing the risk, cost, and time often associated with the remediation of non-native species. An all-new format consisted of presentations, workshops, exhibition stands and panel discussions. The informal workshops allowed INNSA organisers to tailor sessions to the specific needs of delegates from different occupations and sectors affected by the need to control invasive species such as Japanese knotweed, including property, amenities, and environmental professionals.

The day was opened by INNSA Chairman, James Sherwood-Rogers, who welcomed attendees to the event before explaining more about INNSA’s important work and future plans to acquire new members. Morning sessions provided insight into the impact of invasive species on property, with Mark Sexton of Wiggett Group discussing a developer’s perspective on the plant.

Dorothea Antzoulatos from Charles Lyndon, the legal practice that last year won a landmark ruling in a four year court case against Network Rail, gave an update on the case. The value of the property affected was halved due to the infestation along the railway.  In the afternoon sessions, Barrie Hunt of Monsanto provided an update on Glyphosate following the European Commission’s vote to renew the licensing.  Months of debate were concluded with a vote for a five-year renewal, instead of the fifteen-year extension originally hoped for.

David Layland, joint managing director of Japanese Knotweed Control, teamed up with Tim Bird of CORMAC Limited, a construction management and consultancy firm, to deliver workshops on the management of Japanese knotweed, covering best practice in treating the invasive plant and real case studies of knotweed remediation.

David commented: ““The profile of invasive weeds has increased over in recent years, increasing awareness in most sectors, but also proliferating untrue myths and heightening the risk of misidentification. In reality, any professionals or homeowners with concerns can have peace of mind that the situation is under control, provided that a proper remediation strategy is in place with robust warranties and insurance.”

Delegates were given a case study of a UK housing development, which had Japanese knotweed within and neighbouring the site. Installations of underground cables had resulted in further contamination as ground disturbance caused the contaminated soil to spread. This was having an impact on the value of houses in close proximity to the infestation.  Attendees were given the opportunity to have their say on the case study during the interactive workshop, discussing the legislation that should be considered, the potentially suitable remediation strategies, ecological considerations and costing.

INNSA’s Chairman, James Sherwood-Rogers said: “Japanese knotweed can cause significant damage to property, and is especially costly if treatment is not completed by accredited, qualified, insured specialists. In the amenities space, invasive plants can have hugely negative impact by out-competing natural species, causing soil erosion, and encouraging flooding. The INNSA conference provides a valuable forum for professionals to come together to share expertise and the latest information on how to minimise the risk posed by invasive species such as Japanese knotweed.”

7th February 2019 is the date for next year's event - put it in your diary now.

The UK trade body dedicated to the UK Invasive species industry INNSA (Invasive Non-Native Specialists Association) has launched the new Code of Practice for Managing Japanese Knotweed.

The new Code of Practice replaces the third edition of the Environment Agency document “Managing Japanese Knotweed on development sites” also known as “the knotweed code of practice”, which was withdrawn in 2016 and passed to INNSA for on-going management and updates. Claimed to be the most downloaded document in the history of the Environment Agency, the new Code of Practice represents the highest shared standards of best practice within the industry, written, enhanced and refined by the Association’s senior representatives.

The Code provides a clear understanding of what is required and recommended when dealing with Japanese knotweed remediation works.

The Chairman of INNSA, James Sherwood Rogers states “Expected to be a go-to document for all developers, planners and contractors who may encounter Japanese knotweed in the course of their work, the new Code of Practice will provide a clear understanding of what is required and recommended when managing infested land in an appropriate way.”

The Invasive Non-Native Specialists Association (INNSA) is a not-for-profit industry body for companies involved in controlling and eradicating invasive non-native species in the UK. INNSA aims to improve standards within the industry through providing advice, services and support to its members and influencing the EU and UK policy agenda and guidance on non-native invasive species.   

The invasive and resilient nature of Japanese knotweed means that it has the capacity to cause extensive damage to properties, road verges, rail infrastructure, flood defences, retaining walls and external works. With it now incumbent on any property valuation surveyor to identify and report any Japanese knotweed on the inspected or adjacent properties, the possibility of claims being made is increasing. 

The potential for claims was brought in to sharp focus during a landmark court case earlier this year in South Wales. Network Rail was forced to pay compensation to residents after they claimed the encroachment of Japanese knotweed from the Government body’s adjacent land had damaged their homes and in turn reduced their value. If Japanese knotweed is found then lenders can insist on further specialist inspection and, dependent on the level of contamination, it should either be subjected to a treatment programme with a suitable insurance policy protecting the customer against future infestation.  Japanese knotweed presents continual challenges for local authorities, planners, architects, developers, contractors, consultants and housing associations.  Its handling, management and disposal alone is covered by 10 pieces of legislation including the Control of Pesticides Regulations 1986, The Environmental Protection Act 1990, Hazardous Waste Regulations 2005, The Infrastructure Act 2015 and even the Anti-Social Behaviour, Crime and Policing Act 2014.

For any organisation currently concerned about Japanese knotweed, INNSA’s new Code of Practice provides an excellent starting point to understand the issues surrounding the management of Japanese knotweed and the remedial actions required.

For more information about INNSA’s ‘Code of Practice – Managing Japanese Knotweed’ or to order a copy, please call 0800 1300 485 or email 

Charles Lyndon is a law firm specialising in Japanese knotweed and the law. We have recently been successful on behalf of our client Mr Robin Waistell in a claim in private nuisance against Network Rail Infrastructure Ltd regarding Japanese knotweed. Once liability was established, the issue that remained was what the appropriate remedy would be.

Thursday, 22 June 2017 11:42

BASIS Certification in Crop Protection

Invasive & Injurious Weeds Module

Thursday, 22 June 2017 11:35

Remediation Insurance

From sudden accidental oil spills to slow, gradual pollution, if your business is found liable for environmental damage of any kind you may find the clean-up costs threatening your very business.

Page 1 of 5


Case studies

Latest news