Japanese Knotweed is one of the most invasive plants in the UK.  It can grow in most soil conditions in the UK, but it often resides in man-made areas such as roadside, railways, waste ground, rivers and streams.

If you have Japanese Knotweed on your land, then you must stop it from spreading off your property. This is because it can cause ecological or even physical damage. You don’t have to legally remove Japanese Knotweed from your site unless it’s causing surrounding issues, although you can be prosecuted if you cause it to spread on neighbouring land or into the wild.

Japanese Knotweed can be spread through two main ways:

• Direct rhizome growth
• New plant growth from fragments of other Japanese knotweed plant’s stem or rhizome.

Four Ways to Stop Japanese Knotweed Spreading

If you aren’t experienced in the treatment of Japanese Knotweed than you should contact a specialist who will have the appropriate skill and knowledge.

1. Chemicals 

Using only approved herbicides, you can spray or inject the stems to help kill the plant and stop it from spreading.

You might have to re-spray the plant for a period of 3 years because Japanese Knotweed rhizomes can remain dormant in the soils for many years.

There are several things you might need to follow:

• Anyone spraying herbicides hold a certificate of competence or work under a direct supervisor who holds a certificate.
• Conduct a Control of substance to health assessment.
• Get permission from Natural England if your site is a protected area.
• Get permission from the EA if the plant is located near water.

If you’re looking to dispose of certain chemicals, then you may need one of the following:

• An environment permits
• A waste exemption
• Trade Effluent Consent

2. Bury 

You can bury the dead canes of Japanese Knotweed by composting them, as long as they have been cut (not pulled) a minimum of 10cm above the crown.

If you intended to bury Japanese Knotweed on site, then you need to inform the Environment Agency at least one month prior.

If you are burying Knotweed material, it needs to be:

• On the site it came from, including any ash or soils containing potential knotweed.
• At a depth of at least 5 metres if you haven’t seal with a geotextile membrane.
• At a depth of at least 2 metres if you have seal with a geotextile membrane.

Geotextile membranes that are used for Japanese Knotweed Bury need to be:

• Undamaged
• Large enough to minimise the need for seals
• Seal securely
• Remain intact for 50 years
• UV resistant

If you are unsure on burying Japanese Knotweed, then you can hire an experience contractor with experience and knowledge. Checking for a relevant trade body will ensure that the contractor is a part of an assurance scheme.

3. Burn 

If you are a business and want to burn Japanese Knotweed, then there are a few things that you’ll need to do:

• Inform the Environment Agency at least a week prior to burning
• Inform your local environment health officer at the local council
• Get a burning waste in the open exemption
• Follow local byelaws and not cause a nuisance

For individuals you’ll only need to check with your local council to see if they allow burning.

Japanese Knotweed crowns and rhizomes may survive burning, so you must follow the guidance on how to bury or dispose of it off site.

4. Disposal Off-Site 

Often you may be unable to dispose of Japanese Knotweed on-site, so you will need to send it to an off-site facility that has a valid permit to accept the material.

You must use a registered waste carrier to transport the waste and a suitable disposal site or landfill that can accept it.

If you are transporting Japanese Knotweed waste, you need to:

• Check with the waste site to make sure they have a permit to accept the material.
• Inform the waste site that you are transporting Japanese Knotweed waste.
• Get an environmental permit to transport and dispose of controlled waste
• Operate within the conditions in treatment and disposal of invasive non-native plants: ROS 178.

Contact GMAT

You can get in touch with GMAT if you need permitted disposal facilities for treated soils that have been infected with invasive weeds.

Phone: 0161 647 7409

Email: info@gmat.co.uk

We can accept a wide range of invasive plants including Japanese Knotweed, Himalayan Balsam, Giant Hogweed & Marestails.