Japanese knotweed and invasive plants: your landlord's duty

In short

Japanese knotweed is one of the most aggressive invasive plants in the UK. It pushes through concrete. It damages walls and footings. It can make a home impossible to mortgage. Your landlord carries a legal duty to control it. Is it damaging your home while the landlord does nothing? The free routes below get it acted on fastest.

What Japanese knotweed is

Japanese knotweed is a fast-growing plant, brought to the UK in the 1800s. It spreads through roots that run underground. The roots travel metres beyond the plant you can see. Even a small piece of root grows into a new plant.

You can spot it by:

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

It dies back in winter, but the roots live on underground and regrow in spring. Ground that looks clear may hold live roots for years.

Why it is serious

• Damage: the roots find cracks in walls, drains, patios and footings, and widen them over time
• Mortgages: the Royal Institution of Chartered Surveyors (RICS) has issued guidance on knotweed, and many lenders refuse or limit a mortgage where it is or was present, short of a management plan
• Value: unmanaged knotweed can knock a lot off a home's worth
• Legal risk: knotweed allowed to spread onto a neighbour's land can bring civil and criminal trouble

Your landlord's legal duty

The Environmental Protection Act 1990 never names knotweed as a plant that must be destroyed. But letting it spread next door can count as a nuisance. A landlord can face prosecution, or a civil claim.

The Infrastructure Act 2014 lists knotweed as an invasive non-native species. Councils hold powers to make landowners control it.

Where knotweed is damaging your home, or about to, the landlord's repair duties under Section 11 of the Landlord and Tenant Act 1985 may also apply. Damage to drains, footings, or other parts of the structure becomes a repair issue.

Is the tenant ever liable?

In most tenancies, knotweed is not the tenant's job. It is a building and land issue, and it sits with the landlord. Still, check your tenancy agreement: some private ones carry clauses about the garden. Even then, the cost of proper treatment would normally fall to the landlord once the plant takes hold.

What to do if you spot it

1. Never dig it up or cut it down yourself. Disturbed roots spread the plant further. Disposing of knotweed the wrong way is a criminal offence under the Environmental Protection Act 1990.
2. Take dated photos showing the plant and where it grows.
3. Report it to your landlord in writing. Say where it grows and name any cracks or damage near it.
4. Ask for the landlord's plan. Proper treatment usually means weedkiller over two to four growing seasons, often by a contractor on the Property Care Association register.
5. Contact your council where the landlord stays silent. It can require action under invasive species law.

Free ways to get knotweed dealt with

Knotweed is not something we take on, but free routes exist to get it acted on:

• Report it to your landlord in writing and keep a copy. Spreading from land they answer for may mean they must control it.
• Get a qualified surveyor to confirm the plant and the treatment needed.
• Contact your council, which can require action under invasive species law.
• For free, independent advice on your options, contact Citizens Advice or Shelter. 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)