Japanese knotweed and invasive plants: your landlord's duty

Direct answer

Japanese knotweed is one of the most aggressive invasive plants in the UK. It can push through concrete, damage walls and foundations, and make a property impossible to mortgage. Your landlord has a legal duty to control it. If it is causing damage to your home and your landlord is doing nothing, you may have grounds for a disrepair claim. Call us free on 0800 030 4669.

What Japanese knotweed is

Japanese knotweed is a fast-growing plant that was introduced to the UK in the nineteenth century. It spreads through its underground root system, known as rhizomes, which can travel several metres from the visible plant. Even a small fragment of root can grow into a new plant.

It is recognisable by:

• Hollow bamboo-like stems with purple speckles
• Large, heart-shaped leaves arranged in a zigzag pattern
• Small cream or white flowers in late summer

It dies back in winter, but the roots remain alive underground and regrow in spring. Even cleared ground may have live rhizomes for years.

Why it is serious

• Structural damage: the root system can exploit cracks in walls, drains, patios, and foundations, widening them over time
• Mortgage impact: the Royal Institution of Chartered Surveyors (RICS) has issued guidance on knotweed, and many lenders will decline or restrict mortgage applications on properties where knotweed is present or has been present without a management plan in place
• Property value: the presence of knotweed without active management can reduce the value of a property significantly
• Legal liability: allowing knotweed to spread onto neighbouring land can result in civil and criminal liability

Your landlord's legal duty

Under the Environmental Protection Act 1990, Japanese knotweed is not explicitly named as a species that must be destroyed, but allowing it to spread onto neighbouring land can amount to causing a nuisance and a landlord can face prosecution or a civil claim.

Under the Infrastructure Act 2014, Japanese knotweed is listed as an invasive non-native species. Local authorities have powers to require landowners to control it.

Where Japanese knotweed is causing or threatening structural damage to your home, the landlord's repair obligations under Section 11 of the Landlord and Tenant Act 1985 may also apply. If the plant damages drains, foundations, or other parts of the structure, that becomes a repair issue.

Is the tenant ever liable?

In most tenancies, tenants are not responsible for dealing with Japanese knotweed. It is a structural and land management issue, which sits with the landlord. However, check your tenancy agreement. Some private tenancy agreements include clauses about the condition of gardens, though even then the cost of professional knotweed treatment would normally fall to the landlord for an established infestation.

What to do if you spot it

1. Do not dig it up or cut it down yourself. Disturbing the roots can spread the plant further. Disposing of knotweed incorrectly is a criminal offence under the Environmental Protection Act 1990.
2. Take dated photographs clearly showing the plant and its location on the property.
3. Report it to your landlord in writing, describing where it is growing and any signs of structural concern near it.
4. Ask your landlord for their management plan. Professional treatment usually involves herbicide applied over two to four growing seasons. They may use a contractor registered with the Property Care Association.
5. Contact your local council if the landlord does not respond. The council can require action under invasive species legislation.

How this connects to a disrepair claim

If Japanese knotweed or another invasive plant (such as giant hogweed, Himalayan balsam, or buddleia) has caused structural damage to your home, and your landlord has been notified but has not acted, the resulting damage may form part of a housing disrepair claim. The key tests are:

• The landlord knew about the problem (or should have known)
• The plant has caused damage to the structure or fittings of the property
• The landlord has not taken reasonable steps to address it

Where we fit in

Support for Tenants helps with housing disrepair claims. If invasive plant growth has caused real damage to your home and the landlord has done nothing after being told, you may have a claim. No upfront cost. You only pay if you win, and the fee comes out of the compensation, not your pocket. If you don't win, you pay nothing. Call us free on 0800 030 4669, send the short form, or message us on WhatsApp. See also where to get other housing help.

Sources

• Environmental Protection Act 1990 (legislation.gov.uk)
• Infrastructure Act 2014, Schedule 9 (legislation.gov.uk)
• Anti-social Behaviour, Crime and Policing Act 2014 (legislation.gov.uk)
• Section 11, Landlord and Tenant Act 1985 (legislation.gov.uk)