A Japanese knotweed expert has shared one of the “big problems” sellers may not know about the plant which could leave them in hot water further down the line. Japanese knotweed is less noticeable in the winter months as it dies back to ground level. However, in the early summer, the bamboo-like stems emerge from rhizomes deep underground and can grow to be more than two metres tall.
To eradicate or control the plant, homeowners have to choices – herbicide or excavation.
A herbicide program could take around two years of spraying and then a further two years of monitoring, according to Nic Seal, Managing Director of Environet, a leading specialist in Japanese knotweed and other invasive plants.
Nic previously told Express.co.uk that using herbicide is just a “controversial method” and will not remove or eradicate the plant completely.
He added: “The reason for that is knotweed has this clever ability to go dormant and that dormancy can last for 10 possibly 20 years.”
When the plant is dormant, the root system is not dead but simply asleep.
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A seller has to fill in a form known as a TA6 Property Information Form when they come to sell their home.
The form allows the seller to divulge important information about the property being sold to the buyer.
It asks a variety of questions and the seller is required to be as thorough and truthful as they can in answering these questions.
One of the form’s standard questions reads, “is the property affected by Japanese knotweed?”. Sellers are given three boxes to tick; either “yes”, “no” or “not known”.
But Nic said there is a “big problem” people don’t understand about knotweed – it can lie dormant for years.
“If you can imagine, you’re living in a property and there’s nothing growing, there’s no knotweed, and you put ‘no’ on the TA6 form, and the next spring when you’ve sold [the property], knotweed starts to grow… that buyer is going to feel very aggrieved by the fact you said there wasn’t any and there clearly was.
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“So there’s quite a lot of misrepresentation claims brought for people who have answered that question falsely.
“It may be that they’ve answered that question falsely but innocently or it may be that they answered it negligently or it may be that they’ve answered it fraudulently.
“If they’ve done it negligently or fraudulently, they’re almost certainly going to be forking out quite a lot to settle the claim or go to court and pay the damages and the costs awarded against them.”
Nic warned sellers against “burying their heads in the sand” or attempting to conceal knotweed from a potential buyer.
“That really isn’t a very sensible approach I don’t think,” he added.
Sellers who are unsure whether knotweed on their property can hire specially-trained detection dogs from Environet to sniff out the rhizomes.
A professional will be able to do a visual survey of the property to check for knotweed and the dogs will sniff the ground to see if they can detect the scent of the rhizome.
The detection dogs have a 99 percent accuracy rate, according to Environet, making them a reliable method for assessing the risk of knotweed presence on a property.
A homeowner who is unsure whether a property has knotweed should always check before ticking “no” on a TA6 form when selling a property.
Nic continued: “The guidance to that form says, ‘do not answer no unless you’re absolutely certain that no rhizome lies in the ground of the property or within three metres on an adjoining property’.
“My challenge to anyone would be, how on earth can you ever be sure that there’s no rhizome?
“Just because there’s nothing growing above ground, does not mean there’s no rhizome there.”
For homeowners who have only lived in a property for a few years, it’s unlikely they will know for sure there are no rhizomes growing underground.
“You don’t know so the correct answer is ‘not known’ to that question. If you answer ‘no’, you are giving the buyer the categorical reassurance that there isn’t any and they are entitled to rely on that answer,” he added.