How you can identify, control and get rid of Japense Knotweed, Britain’s most invasive plant

Japanese Knotweed in full flow (Image: Archant)

Concerns have been raised locally about tackling the fast-growing weed, which can grow through brickwork and concrete and costs around £165 million a year to control in the UK.

The plant can grow as much as 20cm a day and has roots that can extend three metres in depth and seven metres in all directions; growing into building foundations and drains, causing serious damage.

Where it is found on land and open spaces within the council’s control, the council is taking action to reduce the risk of spread and eradicate it. The council’s grounds maintenance contractor has also been trained in identifying the weed and treating it.

Responsibility for controlling Japanese Knotweed rests with the landowner or occupier of the land - you do not have to remove the plant from your land, but you could be prosecuted if you allow it to spread onto someone else’s property.

Council leader, councillor John Clark, said: “The council takes its responsibility with regards to open spaces and the land that we manage seriously. However, the council does not have the resources in terms of people, nor finance, to be assessing knotweed on land that it is not responsible for.

“It is important homeowners are aware of the potential damage Japanese Knotweed can cause, and follow guidance from the Environment Agency to help control and manage it.”

People can follow the following advice to help identify Japanese Knotweed on their land, and manage and deal with it in the right way:

Identifying Japanese Knotweed:

• produces fleshy red tinged shoots when it first breaks through the ground

• has large, heart or spade-shaped green leaves

• has leaves arranged in a zig-zag pattern along the stem has a hollow stem, like bamboo

• can form dense clumps that can be several meters deep

• produces clusters of cream flowers in late summer

• dies back between September and November, leaving brown stems.

Getting rid of Japanese Knotweed:

• Do not try to cut the weed down, mow or strim as this will make it spread.

• Please do not put Japanese Knotweed in your green bin (normal household waste) or brown bin (garden waste), or take it to a recycling centre – it must be disposed of as controlled waste.

• For more advice on how to control and dispose of Japanese Knotweed, including chemical spraying and burning, visit: https://www.gov.uk/guidance/prevent-japanese-knotweed-from-spreading. The site also contains a link to local controlled waste carriers who can dispose of the weed legally.