Japanese Knotweed

Invasive Non-native Plants

Invasive non-native plants are species that have been brought into the UK and that have the ability to spread, causing damage to the environment, the economy, our health and the way we live.

Invasive non-native plants can cause problems for native UK species and reduce biodiversity (the variety of living organisms). Invasive non-native species are now widely recognised as the second biggest threat to biodiversity worldwide. Japanese knotweed can block footpaths and damage concrete, tarmac, flood defences and the stability of river banks. Giant hogweed can cause harm to human health.

More information is available on the RHS website.

Japanese Knotweed

Japanese Knotweed is a native plant in Japan, Taiwan and northern China, but is an extremely invasive plant in the UK. It thrives on disturbance and the tiniest piece can re-grow and spread.

You are not legally obliged to remove these plants from your garden, but if you allow the Japanese Knotweed to grow onto other people's property, they could take a private nuisance action against you.

If you believe you have Japanese Knotweed growing in your garden, you should deal with it as quickly as possible. Identification is important, as Japanese Knotweed can be confused with other plants including:

• Fallopia baldschuanica (Russian vine)
• Leycesteria formosa (Himalayan honeysuckle)
• Houttuynia cordata
• Persicaria microcephala (e.g. P. microcephala 'Red Dragon')

It would be advisable to notify your neighbours if you believe you have Japanese Knotweed in your garden in order for them to ascertain whether it is present in theirs. Early identification and treatment will contain the plants from further spreading. If you need to notify your neighbours, a suggested format could include the following:

"We have recently discovered Japanese Knotweed growing in our garden. We are taking action immediately to control and, eventually, eradicate this plant.

As it is very invasive it would be advisable that you check your garden to see if you also have this plant so that you can start your own control measures. There is information available on Stratford-on-Avon District Council's website that you may find useful on how to identify and control the spread of these plants."

Removing Japanese Knotweed

You can find advice on removing Japanese knotweed and other non-native invasive species on the RHS website.

Please note that, under the Environmental Protection Act 1990, Japanese knotweed is considered controlled waste. The plant or any soil containing the plant would have to be disposed of by a suitably licensed waste carrier at an appropriately licensed waste site. For further advice on this please visit DEFRA.

Under no circumstances should Japanese knotweed waste be placed in domestic waste bins or fly tipped elsewhere.

If you believe your neighbours have Japanese knotweed growing on their property

If you believe that your neighbours have Japanese Knotweed growing in their garden and that there is a risk of it spreading to your garden, or it already has spread to your garden, it is advisable to contact them asking them if they are aware of the problem. You should ask them to confirm that that they will put measures in place to control the spread to your garden.

In the first instance, a suggested format could include the following:

“We believe that you may have Japanese Knotweed growing in your garden.

We thought you would want us to make you aware, as it is recommended that a management programme be put into place to control the spread of this plant onto my property. I'd be grateful if you could contact me to discuss the matter further.

We will, of course, regularly monitor our garden to ensure that any spread is dealt with immediately and will keep you informed if any is discovered.

We look forward to hearing from you."

You should allow four weeks for your neighbour to respond. If they fail to do so, you should write a second letter restating the contents of the first letter and asking them to confirm their intended actions.

A suggested format for a second letter could include the following:

“We wrote to you recently informing you that we believe you may have Japanese Knotweed growing in your garden. You are not legally obliged to remove this plant, but if you allow Japanese Knotweed to grow onto my property you could be prosecuted for causing a nuisance.

Recent changes in legislation have given local authorities powers to take legal action, where necessary, against the owners of private land where non-native invasive plant species are invading neighbouring properties.

If you do not reply to our letter informing us that measures will be put into place to control the spread of this plant onto my property, we will inform Stratford-on-Avon District Council, which has the power to issue a Community Protection Notice."

If, after a further four week period, you have still not had any response to either of the letters you have sent, please contact us on 01789 267575 or env.health@stratford-dc.gov.uk.

Recent changes in legislation have given the council the power to take legal action against the owners of private land where non-native invasive plants like Japanese Knotweed are invading neighbouring properties.

Under the Anti-social Behaviour Crime and Policing Act 2014, we can issue land owners with a Community Protection Notice to formally require them to control the spread of Japanese knotweed on their land. However, we would only consider this where residents are taking no action and causing Japanese knotweed to significantly spread onto neighbouring land.

For us to take up your case, it will be necessary for you to provide copies of the letters you have sent to your neighbour and also for the case to meet certain criteria.