Prevent Japanese knotweed from spreading
How to identify, control and dispose of Japanese knotweed.
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You must prevent Japanese knotweed on your land from spreading into the wild and causing a nuisance.
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.
Find out how to identify Japanese knotweed using the identification sheet.
Prevent the spread of Japanese knotweed
You don’t 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.
Spray with chemicals
Spraying with chemicals (known as ‘herbicides’) is an effective treatment to stop invasive plants from spreading. You must only use approved herbicides.
You’ll have to re-spray. 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 (COSHH) assessment
- get permission from Natural England if the area is protected, eg sites of special scientific interest
- get permission from the EA if the plants are near water
You might need any of the following to dispose of certain chemicals:
You must dispose of chemicals through a registered waste carrier to a permitted waste disposal facility.
Before burying non-native invasive plant waste on your land check with the EA to see if this is allowed. You won’t normally be allowed to bury waste on land unless it’s at a landfill site that’s got a suitable permit.
You can bury Japanese knotweed at the site where 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 doesn’t allow the plant to grow through it (known as a ‘root barrier membrane layer’)
- make sure that you don’t bury any other types of waste with it
Where it isn’t possible to bury the plant 5 metres deep, you should wrap a root barrier membrane layer completely around the plant remains and bury it at a depth of at least 2 metres.
You may need to tell the EA a week before you intend to bury the plant waste. Send a letter to your local area EA team.
If you’re a farmer burning Japanese knotweed plant waste, you must tell:
You don’t 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. Knotweed crown and rhizome may survive burning, therefore you should dispose of any remaining material following the guidance on burial or off-site disposal on this page.
Dispose off-site safely
Soil or plant material contaminated with non-native and invasive plants can cause ecological damage and may be classified as controlled waste.
It’s an offence to keep, treat or dispose of waste that could harm:
- the environment
- human health
You must use a registered waste carrier and an authorised landfill site or suitable disposal site. To find a site that accepts the waste you can check with the site direct, contact your local authority or check the EA public register. You can’t usually compost most non-native plants because of all of the following:
- they’re usually persistent
- they’ll survive the composting process
- they usually infest areas where the compost is used
You must follow the law if you’ve been employed to transfer goods or material by road (otherwise known as being a ‘haulier’) and you’re disposing of any waste that has or might have Japanese knotweed in it.
Dispose of Japanese knotweed waste off-site
You must dispose of Japanese knotweed waste off-site by transferring it to a disposal facility that’s permitted, eg a landfill site that has the right environmental permit. The permit must allow the disposal of invasive plants at the landfill site but it won’t necessarily specify invasive weeds. Usually the permit will allow biodegradable wastes to be taken and will usually be for non-hazardous wastes.
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 can’t get a waste licensing exemption for the use of Japanese knotweed.
Transfer Japanese knotweed waste
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 the plant or rhizome
See the Japanese knotweed code of practice for more information.
Contact the Environment Agency for help if you:
- have further questions about to how to handle Japanese knotweed
- want to find out more about when you need a waste licence to dispose of waste
- want to complain about waste producers who aren’t telling people they employ to transfer waste material about Japanese knotweed in that waste - this is breaking the rules on their waste duty of care
National Customer Contact Centre
PO Box 544
Telephone: 0370 850 6506