Researchers at Swansea University have carried out a three year study into the eradication of Japanese Knotweed

This included nineteen different methods and a variety of chemical solutions - and have concluded that there is no definite cure for the invasive plant. 

But what is Japanese Knotweed and why should homeowners be cautious?

Japanese Knotweed is a plant characterised by its thick, bamboo-like roots which are capable of boring through walls and foundations. It is fast growing and easy to spread, if not managed appropriately. 

The removal of knotweed is strict. Pulling the plant at the root can release spores into the air, allowing the seed to travel and re-plant itself. It cannot be disposed of like normal plant waste. Knotweed is, in fact, classified as controlled waste under the Environmental Protection Act and can only be disposed of at licensed landfill sites. 

There are specialist companies to assist in the removal of knotweed and a treatment plan (often spanning five or ten years, or more) has to be implemented which may be at significant cost to the homeowner.  The Telegraph reports that knotweed costs the UK Economy £166m a year in home devaluations and the expense of treating it.

So what should you do if you become aware of knotweed on your land?

Firstly - don’t ignore it! Whilst it is not a criminal offence to have knotweed on your land, if you fail to control it you may be liable to enforcement action under the Anti-social Behaviour, Crime and Policing Act 2014. You should not try to remove the weed yourself, but instead instruct a specialist removal company. Knotweed can significantly damage the foundations of your property (and the foundations of neighbouring properties) so early action is essential. 

If you are thinking of buying a property which is affected by knotweed, speak to your legal advisor first before proceeding. If you are buying with the assistance of a mortgage, your solicitor is under an obligation to disclose anything which may affect the value or marketability of the property so will need to report the existence of knotweed at the earliest opportunity and seek the lender’s guidance on how to proceed. 

Whilst the study by Swansea University has found that knotweed cannot ever truly be cured, it can be managed. RICS and the Property Care Association have created the Invasive Weed Control Group which provides a register of knotweed consultants and contractors. More information can be found on the RICS website -

Our specialist solicitors can advise on a wide range of property transactions. For more information, please contact us on 0161 941 400 and ask to speak to the Residential Property Team or email

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