How to identify, prevent spread and dispose of Japanese knotweed.
Applies to England and Wales
Identify Japanese knotweed
Prevent spread of Japanese knotweed
You must prevent Japanese knotweed on your land spreading into the wild.
Soil or plant material contaminated with non-native and invasive plants like Japanese knotweed can cause ecological damage and may be classified as controlled waste.
You do not have to remove Japanese knotweed from your land, but you could be prosecuted or given a community protection notice for causing a nuisance if you allow it to spread onto anyone else’s property.
Many non-native plants cannot be composted because they:
- are usually persistent
- will survive the composting process
- usually infest areas where the compost is used
Spray with chemicals
Spraying with chemicals can be an effective treatment to stop invasive plants from spreading. You must only use approved herbicides.
You’ll have to respray. It usually takes 3 years to treat Japanese knotweed until the underground rhizomes become dormant.
You may need to do any or all of the following when using chemicals:
- make sure anyone spraying holds a certificate of competence for herbicide use or works under direct supervision of a certificate holder
- carry out a Control of Substances Hazardous to Health assessment
- get permission from Natural England if the area is protected, for example sites of special scientific interest
- get permission from the Environment Agency if the plants are near water
You may need any of the following to dispose of certain chemicals:
Before burying non-native invasive plant waste on your land, check with the Environment Agency to see if this is allowed. You will not normally be allowed to bury waste on land unless it’s at a landfill site that has a suitable permit.
You can bury Japanese knotweed at the site it’s produced as long as you:
- bury it at a depth of at least 5 metres
- cover the plant remains with a material that does not allow the plant to grow through it (known as a root barrier membrane layer)
- do not bury any other types of waste with it
Where it’s not possible to bury the plant 5 metres deep, you should wrap a root barrier membrane layer completely around the plant remains and bury them at a depth of at least 2 metres.
You may need to tell the Environment Agency a week before you intend to bury the plant waste.
If you are a business that wants to burn Japanese knotweed you must tell:
- the Environment Agency at least a week before you burn it
- the environmental health officer at your local council
You do not need to do this if you’re burning the waste privately as an individual but you should check with your local council that burning is allowed.
Japanese knotweed crown and rhizome may survive burning, so you must dispose of any remaining material following the guidance under how to ‘bury it’ or how to ‘dispose of it’ off-site.
How to dispose of Japanese knotweed
You could be fined up to £5,000 or be sent to prison for up to 2 years if you allow contaminated soil or plant material from any waste you transfer to spread into the wild.
You can supervise the management and disposal of Japanese knotweed yourself, or you can hire a specialist to do it for you.
The Environment Agency does not endorse any specialist offering Japanese knotweed treatment. You must make sure that the specialist you use:
- operates within the conditions in Treatment and disposal of invasive non-native plants: RPS 178
- has the relevant environmental permit
You do not need to hire a specialist contractor to treat Japanese knotweed, but there are a number of companies that specialise in Japanese knotweed treatment. Many of these companies belong to one of these trade bodies:
Use a waste carrier to take Japanese knotweed off-site
You must use a registered waste carrier and an authorised landfill site or suitable disposal site.
You must follow the law if you’ve been employed to transfer goods or material by road and you’re disposing of any waste that has or might have Japanese knotweed in it.
You must dispose of Japanese knotweed waste off-site by transferring it to a disposal facility that’s permitted, such as a landfill site that has the right environmental permit.
You must not:
- dispose of Japanese knotweed with other surplus soil
- sell soil contaminated with Japanese knotweed as topsoil
You can only reuse knotweed-contaminated soils after treatment, on the site where they were produced.
You cannot get a waste licensing exemption for the use of Japanese knotweed.
Before you transfer Japanese knotweed waste you must:
- check with the waste site in advance to make sure it’s got a permit to accept material containing invasive plants – the waste site may also need time to prepare
- tell the waste site that you’re transferring Japanese knotweed waste
When you transfer the Japanese knotweed waste you must cover or enclose it in the vehicle so that no waste can escape.
After you transfer Japanese knotweed waste
After you’ve transferred the Japanese knotweed waste at the disposal site you must:
- brush vehicles down vigorously or jet-wash them to clear them of any Japanese knotweed
- inspect your vehicles to check there’s no trapped pieces of plant or rhizome
You do not need to report the presence of Japanese knotweed on your land. You can contact the Environment Agency for help if you:
- have more questions about how to handle Japanese knotweed
- want to find out more about when you need a licence to dispose of Japanese knotweed
- want to complain about waste producers who are not telling people they employ how to transfer Japanese knotweed – this is breaking the rules on their waste duty of care
Monday to Friday, 8am to 6pm.
The impact of COVID-19 means you may experience some delays in responses.