News & Insights

Untying the knots of Japanese Knotweed…

What is Japanese Knotweed?

Japanese Knotweed is a rapidly-growing and invasive weed. It often grows into dense thickets and can be identified by its bamboo-like stems that develop shield shaped leaves.

What are the risks of Japanese Knotweed for Landowners, Developers and Buyers?

Japanese knotweed can cause physical damage to buildings and surrounding land as it can penetrate concrete, foundation and walls and weaken their structure. This can affect the value, insurability and marketability of the land as well as the ability to secure a mortgage against it.

Japanese knotweed is also difficult to remove. Even if a small part of the stem or root is left behind, it can re-infest the land. Removal costs are very expensive.

The presence of Japanese knotweed can also have significant environmental impact as the weed is known to threaten other plant life and increase flood risks.

What does the Law say about Japanese Knotweed?

The law states that planting or causing Japanese knotweed to grow in the wild is a criminal offence, which carries a fine of up to £5,000 and/or imprisonment of up to 2 years. This includes allowing contaminated soil or plant material from any waste to spread into the wild.

A landowner can also be liable if Japanese knotweed on their land spreads to neighbouring property. In recent cases, Waistell and Smith v Line, the Claimants were able to recover damages and obtain an injunction requiring the defendant to treat the Japanese knotweed (respectively) on the basis that the Japanese knotweed reduced the value of their land.

It is worth noting that the standard legal forms used in sales also specifically enquire about the presence of Japanese knotweed and so a seller must disclose any Japanese knotweed to their buyer.

How can Japanese Knotweed be removed or managed?

Please see the following guidance on the Government website:

There are various methods of removing or managing the growth of Japanese knotweed although given the high risks associated with this menace, landowners, buyers and developers are well-advised to seek specialist advice.

If you wish to discuss further, please contact Foskett Marr Gadsby & Head LLP’s Property Teams, based in Epping and Loughton, on 01992 578 642. Further details on and