Japanese knotweed

Japanese knotweed is an invasive plant that spreads rapidly and damages property. It is the landowner's responsibility to control Japanese knotweed on their property. Find our more about how we can help here.

Japanese knotweed, also known as Fallopia japonica, is an invasive plant that spreads rapidly and crowds out other native vegetation. It can grow almost anywhere, including gardens, parks, and roadsides. 

This aggressive plant can cause significant damage, including

  • Loss of native plant species
  • Structural damage
  • Land value reduction
  • Mortgage difficulties

Recognising Japanese knotweed

Here are key features to help identify Japanese knotweed:

  • Large, green, shovel-shaped leaves

Japanese knotweed leaves are distinctively large and shaped like shovels. They are typically 10-15 centimetres long and have a smooth, glossy surface.

  • Vertical bamboo-like stems

The plant's stems are hollow and can grow up to 3 meters tall. They are typically green but may turn red or purple in autumn.

  • White flowers

Japanese knotweed produces white flowers in late summer or early autumn. The flowers form small clusters along the stems.


Picture of Japanese knotweed.

Controlling Japanese knotweed

Controlling Japanese knotweed can be challenging as it is an invasive species of plant which spreads rapidly and overwhelms other plants. It is crucial to prevent the plant from spreading to other areas.

Landowner responsibility

The landowner is responsible for controlling Japanese knotweed on their property. This includes preventing the plant from spreading to neighbouring lands or public spaces.

Consult landowners

If you find Japanese knotweed on private land, such as a neighbour's property or a construction site, contact the landowner first. If no action is taken, report the issue to the Environmental Health department.

Public or council-owned land

For Japanese knotweed on public or council-owned land, contact the Environmental Sustainability Service.

Proper disposal

Do not remove or dispose of Japanese knotweed on your own, putting it in your bin or local waste centre is an offence. Contact a specialist contractor for proper removal and disposal.

Intentionally spreading Japanese knotweed is an offence. Improper disposal of the plant can also lead to legal consequences.

More information

For more information on Japanese knotweed, including identification, control methods, and legal obligations, visit Gov.uk.

Contact

Environmental Health 

Address

2nd Floor

Municipal Building

Archway Road

Huyton

L36 9FB

Telephone

0151 443 4712

Email

environmentalhealth@knowsley.gov.uk

The Environmental Sustainability Service

Email

ess.enquiries@knowsley.gov.uk

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