Japanese Knotweed – what your clients must know

It is getting close to the time of year where Japanese knotweed begins to rear its head, or buds in this case, and we realise where it has been hiding for the winter. Japanese knotweed is a tricky foe as it dies off during the winter months and looks very similar to the wilderness that surrounds it making it difficult to spot. But as spring rolls around it bursts back into life and can start to cause problems for home owners across the country. Therefore it is important to keep reminding our clients of what they’re up against and what the implications of this invasive species are. The first thing to be aware of is what it looks like as early identification leads to quicker eradication.

What are we supposed to be looking out for?

Japanese knotweed has several stages of growth each of which has certain identifiable features including the root buds, stems, leaves, flowers and rhizomes (or roots). Details regarding the different stages of these features are as follows 1:

Why is it important to know what we’re up against?

It is important for conveyancers to make clients aware of Japanese knotweed because, as well as its potential for inflicting damage to buildings, there are legal implications for properties at which the plant is present. Whilst it is not an offence to have Japanese knotweed on a property, nor is its presence reportable, it is the land owner’s responsibility to ensure that it does not spread to adjoining land 2. There are three pieces of legislation that provide powers to control the spread of Japanese knotweed:

1. Wildlife & Countryside Act 1981, Section 14 3

  • Under this Act it is an offence to plant or otherwise cause any plant listed in Part 2 of Schedule 9, including Japanese knotweed, to grow in the wild

2. Environmental Protection Act (EPA) 1990, Section 34 4

  • This Act states that Japanese knotweed is classed as ‘Controlled Waste’ and must safely be disposed of at a licensed landfill site. Breach of this Act can result in an unlimited fine and/or a 2 year prison sentence

3. Anti-social Behaviour, Crime and Policing Act 2014 5

  • This Act gives the police and local authorities the power to serve a community protection notice on a body or individual requiring them to prevent or control the growth of Japanese Knotweed. In order to serve a notice it must be proven that there is a persistent or continuing detrimental effect on the quality of life of those around them, and the failure to deal with the problem is unreasonable. Breach of a community protection order can lead to a fine up to £2,500 for an individual or up to £20,000 for an organisation

In addition to these pieces of legislation many local authorities also provide guidance via their websites on what to do in the event Japanese knotweed is discovered at a property.

Outside of the legal implications of Japanese knotweed, it can have a detrimental effect on a property. In particular it can cause structural issues due to its ability to exploit existing cracks in structures including patios, paths, pipes, culverts, foundations, brick work, etc. and services as it grows in search of nutrients, light and water 6.

It is because of this and amendments to legislation that resulted in the Law Society revising the TA6 Property Information Form in 2013 to include a question (7.8) about whether or not the property has been affected by Japanese knotweed. If a vendor declares the property is free of knotweed and it is later discovered they may be liable for diminution in value and treatment costs 7. To treat an area of knotweed of only a few metres squared costs can range from £5,000 to £10,000 and sometimes more if a quick resolution is needed 3.

How can it be dealt with?

As a home owner would be responsible for ensuring Japanese knotweed does not encroach onto neighbouring land it is also important to make your clients aware of the ways in which it can be dealt with, which include 8:

  • Chemical Treatment
  • Relocation and Herbicide Programme
  • Reduced Dig and Herbicide Programme
  • In-Situ Capping
  • On-site Burial
  • Picking, Screening and Sorting
  • Excavation and Removal
  • Biological Control

Full details regarding all of the above mentioned treatment methods can be found in the Groundsure Japanese knotweed guide. Groundsure also have a range of videos on Japanese knotweed available on their website.

Having reviewed what we are on the lookout for, why we should be looking out for it and what we can do to get rid of it, it is quite clear to see that Japanese knotweed is a very tricky character to deal with and requires property/land owners and their conveyancers to be constantly vigilant in the battle against this plant.

Richard Schofield, Director, Phlorum commented: “Japanese knotweed is a growing issue for land/property owners, identifying it ahead of the purchase will enable buyers to take appropriate action and could save them both time and money.”


1. Phlorum (2016). How to Identify Japanese Knotweed. UK, http://www.phlorum.com/resources/knotweed-identification/, accessed 19th March 2016.

2. Royal Horticultural Society (2014). Japanese Knotweed. UK, https://www.rhs.org.uk/advice/profile?PID=218, accessed 19th March 2016.

3. Groundsure (2016). Japanese Knotweed: Your definitive guide to identifying, reporting and remediation of Japanese knotweed. UK, http://www.groundsure.com/products/commercial/japanese-knotweed, accessed 19th March 2016.

4. Phlorum (2015). Japanese Knotweed: The Legal Framework. UK, http://www.phlorum.com/blog/2015/02/20/japanese-knotweed-the-legal-framework/, accessed 19th March 2016.

5. Ben Lindley (2014). Anti-Social Behaviour Powers and Knotweed. UK, http://japaneseknotweed.co.uk/news/2014/10/anti-social-behaviour-powers-knotweed/, accessed 19th March 2016.

6. Environet UK Ltd (2016). What type of damage is caused by Japanese knotweed? UK, http://www.environetuk.com/Japanese-Knotweed-Frequently-Asked-Questions/What-Type-Of-Damage-Is-Caused-By-Japanese-Knotweed, accessed 19th March 2016.

7. Law Society (2013). TA6 property information form: explanatory notes. UK, http://www.lawsociety.org.uk/support-services/advice/articles/ta6-property-information-form-explanatory-notes/, accessed 19th March 2016. 8. Phlorum (2016). Knotweed Treatments. UK, http://www.phlorum.com/services/japanese-knotweed/treatments/, accessed 19th March 2016.

(all images supplied by Phlorum)

This article was submitted to be published by Groundsure as part of their advertising agreement with Today’s Conveyancer. The views expressed in this article are those of the submitter and not those of Today’s Conveyancer.

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