The first Japanese knotweed shoots to emerge in 2022 have been spotted on the banks of the River Plym in Plymouth, Devon, more than a fortnight earlier than last year.
Japanese knotweed hibernates during the winter months before emerging when the ground temperature reaches around 4°C.
Traditionally this has occurred during late March/early April, but in recent years Japanese knotweed has begun emerging earlier, possibly due to the impact of climate change.
An RICS report last year said an estimated 1.45 million UK homes are affected by knotweed, which can devalue a property or cause sales to fall through.
However the report said this was largely due to incorrect information about the plant and its disruptive capabilities, and that with appropriate remediation from experts the worst needn’t happen.
‘Not a death sentence for home sales’
The report’s author, Philip Santo FRICS, said: “Creating confidence and awareness that knotweed isn’t a death sentence for home sales is a key principle behind this guidance – it’s certainly not the ‘bogey plant’ that some make it out to be.
“In most instances the weed can be remediated with effective treatment – so it’s critical that all those involved in the home-buying and selling process have access to unbiased, factual information, that sets out when they need to obtain reputable remediation services.”
RICS has just published an updated framework for objectively assessing and reporting the risk posed to a property by the presence of Japanese knotweed, which can be downloaded here.
Homeowners must declare the presence of knotweed on the TA6 conveyancing form when they sell their home, even if it has been successfully treated, and mortgage lenders may require a professional treatment plan to be in place, with an insurance-backed guarantee, before lending on an affected property.
Homeowners and buyers who are unsure whether their property is affected can commission a survey. One specialist firm, Environet, has a team of highly-trained sniffer dogs that will scour a property for signs of knotweed growth – and can even detect the unique scent of the plant’s rhizome beneath the ground.
How to identify Japanese knotweed
Japanese knotweed has red or purple asparagus-like shoots that quickly turn into green bamboo-like stems, growing at a rapid rate to reach approximately three metres in height by June. When mature, the plant has flat, heart-shaped green leaves and blooms in late summer, when its stems become covered in tiny creamy-white flowers.
Emily Grant, Environet’s regional director for the South-West, said, “Homeowners across Devon and Cornwall should be vigilant for the distinctive red or purple spear-like shoots emerging in their gardens or near their homes over the next few weeks, as the knotweed growing season becomes established.
“Those who discover Japanese knotweed on their land should seek professional advice. Implementing a professional treatment plan is the best way to prevent knotweed from causing damage to property, preserve the value of your home and protect yourself from the threat of litigation from neighbours if it’s allowed to spread.”
Environet offers a free Japanese knotweed identification service for anyone who wants to confirm whether or not a plant is Japanese knotweed, which is commonly mistaken for other harmless garden plants such as bindweed, Russian vine and lilac. Just email a photo to [email protected].