Don’t Get In A Knot This Summer

Tracey Wilkinson, from Stone Rowe Brewer’s Teddington office, raises the thorny issue of how Knotweed could scupper a house sale… 

The English Summer weather may be as temperamental as ever, but it is undoubtedly a time when many people look at their gardens, watering can in one hand and weed killer in the other. However, not all gardens are as lovely as the one pictured here – and there is one weed your everyday weed killer will not remove: Japanese Knotweed.

You may be surprised to learn that we have had a handful of cases in our conveyancing experience where this has caused a problem in a house purchase or sale and so thought it relevant to let you know a bit more about it.

Japanese Knotweed was introduced to the UK from Japan in 1825 as an ornamental plant – but ornamental plant it is no more! Its bamboo-like stems can grow to over seven feet tall in early summer, with shovel shaped leaves and creamy white flower tassels with a huge network of roots, which suppresses all other growth.

It can grow through cracks in concrete and tarmac causing damage to buildings, foundations, flood defences and can also be found at roadsides and waste places. It is one of the world’s worst invasive species.

In a conveyancing transaction a seller is asked a standard pre-contract enquiry; “Is the property affected by Japanese Knotweed?” The response is primarily “no” or “not known”. But what if the reply is “yes”?

You are not legally obliged to remove Japanese Knotweed, or control it if present in your garden, but you could be prosecuted for a private nuisance if you allow it to grow onto a neighbour’s garden. It is an offence to cause it to

grow in the wild – this can occur as a result of moving contaminated soil. A specialist should be contacted to remove it as it is classed as “controlled waste” and requires disposal at a licenced landfill.

There is unfortunately no environmental method of controlling it yet. The best way to eradicate it is by using chemicals, but it can take several years to remove. But I want to sell my house or buy a house with a mortgage and my surveyor has discovered there is Japanese Knotweed in the garden – “what do I do?!”

• You will need to arrange for remedial treatment by a Property Care Registered firm who provide a Knotweed Management Plan and warranty for up to 10 years for the eradication of Japanese Knotweed.

• You must also make your solicitor aware of the problem as they will need to liaise with your lender.

• You need to approach this problem as you would any other defect in your property and arrange for qualified contractors to deal with the problem!

It’s not a definite ‘no’ if you come across it in a property you would like to buy, but it is something you very definitely need to be aware of and to deal with.

If you are buying or selling a property, please call Tracey on 020 8977 8621 or e-mail her at