General Knotweed, mortgages and treatment
How do I know if it is Japanese knotweed?
The stem is the giveaway. It is hollow, a bit like bamboo, flecked with purple, and it bends at every joint. Leaves are broad and shield-shaped with a straight base, and cream flower sprays show up late in summer. Brown canes stay standing over winter. Sending us a photo is quicker than comparing it with pictures online.
Is it illegal to have knotweed in my garden?
No, owning land with knotweed on it is not an offence. What you must not do is allow it to spread into the wild, and cut or dug material counts as controlled waste. If it moves onto a neighbour's land, they may be able to bring a claim.
Will knotweed stop me getting a mortgage?
Not automatically. A lot of lenders will go ahead when there is a professional survey, a treatment plan and an insurance-backed guarantee that can be passed to the buyer.
How long does treatment take?
Spraying generally runs for three to five growing seasons, then a monitoring period. Excavation is done in a few days, though it costs more.
Can I just dig it out myself?
We would not. Small bits of rhizome grow back, and the soil cannot just be bagged and put out with household waste or taken to the tip.
Does knotweed damage houses?
It exploits weaknesses such as cracks, drains, old paving and flimsy outbuildings. Sound foundations are rarely threatened, yet a stand close to the house can still hurt a valuation or hold up a sale.
What if it is coming from my neighbour?
Commission a survey so the location and the direction of spread are recorded. That document is what you then show the neighbour, or the landlord or owner of the plot next door.
Should I cut it back or strim it?
No. Strimming throws fragments around and weakens a spraying programme. Leave it standing until someone has looked at it.
What do I have to declare when I sell?
The TA6 form asks the question directly. If knotweed is present, say so and include the management plan. An inaccurate answer can come back on you after completion.
How much does knotweed removal cost?
For a typical garden, a spraying programme often comes to somewhere between £1,000 and £3,000 across its whole length. Excavation is dearer because of soil volume and disposal. After the survey you receive a price in writing.
Do you cover all of Widnes?
Yes — Every WA8 address in Widnes, from the riverside at West Bank to the northern edge at Cronton.
