Homeowners are being warned that the unreasonably warm weather in February has prompted the emergence of Japanese knotweed one month earlier than usual.
If you don’t recognise this invasive plant, it can damage your property as well as your neighbours. It can also cause property sales to fall through if knotweed is only recognised when buyers arrange a survey.
Japanese knotweed removal firm Environet says it spotted spring shoots of Japanese knotweed last week in North Devon.
Japanese knotweed hibernates during the winter and starts to grow when the ground temperature reaches around 4°c, usually in late March or early April.
However, the warm weather which averaged 10°c and peaked at 20.6°c in West Wales at end of February has resulted in knotweed to emerge early from its winter slumber.
Environmental scientist Nic Seal, managing director of Environet, says: “In twenty years of operation, I’ve never seen Japanese knotweed appear in February.
"The unseasonably warm weather has awakened the plant from its winter hibernation and prompted it to start growing an entire month earlier than normal. We’re gearing up for an early start to our treatment season to give our customers maximum protection from this highly invasive plant.
“Those who discover knotweed on their land should seek professional advice. They will probably need to put a professional treatment plan in place to protect their property and themselves from the threat of litigation from their neighbours.”
Japanese knotweed blight 'has slashed UK house prices by £20bn'
The knotweed has emerged a whole two months earlier than last year, when it was delayed due to the 'Beast from the East' and didn’t appear until the end of April and into May.
It can be spotted by the red or purple asparagus-like shoots (see below) that sprout from the ground and quickly grow into green bamboo-like stems. It grows at a rapid rate of up to four inches a day and if left unchecked could even knock 10% off your house price.
Environet offers a free Japanese knotweed identification service where homeowners who are worried about a plant can send a photograph for review. If knotweed is identified and a homeowner wants a quote, it will be provided - but the company says there is no obligation.