- Soaring Easter temperatures signal start of super growth of invasive plant Japanese knotweed
- Met Office predicts Easter weekend temperatures soaring past 20°C
- Easter marks start of warmer climate with hottest Spring on record predicted and temperatures topping 26°C
- Mix of warm and wet weather throughout late winter adds to super growing conditions for knotweed, risking damage to properties
Homeowners are being warned to prepare for a ‘Super Spring’ of Japanese knotweed growth as warm temperatures sweep across the UK this Easter, with the invasive plant species risking damage to homes and devaluing house prices by as much as 10%.
This is also of particular concern to conveyancers as it can significantly impact the conveyancing process. But a new online Tracker tool which informs conveyancers of knotweed risk has been launched which provides an interactive online heatmap of knotweed infestation sightings across the UK. This heatmap is a valuable resource for property professionals involved in residential transactions to enable them to build a picture of local knotweed sightings and assess the potential risk to property or site.
The warnings follow Met Office predictions the country is facing its hottest Spring on record, with forecasts of temperatures reaching as high as 26°C. This follows a mix of unseasonably warm weather and heavy downpours of rain in the winter, which has already led to early growth of knotweed.
Cobleys Solicitors’ dedicated Knotweed Help team, which specialises in Japanese knotweed infestation cases, has seen a higher-than-normal spike in enquiries from concerned homeowners.
Mark Montaldo, Solicitor, Head of Litigation at Knotweed Help, comments:
“Usually, we’d only just start to see new knotweed plants emerging late in April or early May, but this year the plants have already grown by a couple of metres.
“Growth will accelerate as much warmer than average temperatures move in. This is at a time when people are typically getting out into their gardens and also one of the busiest times for new houses going onto the market. People are noticing the weeds and are worried about the risk of structural damage and how knotweed can affect their house price.”
The invasive plant can cause damage to homes as it pushes up through cracks in concrete, cavity walls and drains. Japanese knotweed removal firm Environet UK estimates that during the past 20 years knotweed has knocked around £20billion off house prices.
Nic Seal, Managing Director at Environent UK, said:
“The roots of knotweed on mature plants create an extensive network of rhizomes which extend deep into the ground and are hard to kill. Rhizomes are actually quite brittle. Breaking off a small piece the size of your finger-nail can grow into a new plant resulting in rapid knotweed spread. It’s the rhizomes that can cause damage to property and affect mortgage lending, which adversely affects the property’s value.”
Following a milder than average winter and record-breaking temperatures in February 2019, which saw a maximum of 21.2°C recorded at London’s Kew Gardens, new knotweed growth has already been reported in some areas of the UK including London and the South of England.
Mark Montaldo added:
“We’re seeing an increase in knotweed litigation cases due to encroachment. It’s against the law to let knotweed encroach onto surrounding land and property. However, we’re seeing people refuse to treat their own infestations and when it is within seven metres of a neighbouring house, it can start to pose a risk to that house and negatively affect its selling price.
“As this warmer weather is likely to lead to a spread of knotweed, we’d advise people to use this as an opportunity to get outdoors and identify it on their own land and neighbouring properties, and then seek professional support as it’s also illegal to dig up and improperly dispose of knotweed.”
What to look for: The plant has stems that look like bamboo but are green with purple flecks throughout. It has large, shovel-like leaves that grow yellowish-brown in spring and become a lush green during the summer, with the weed flowering into small white clusters throughout the autumn.
As a conveyancer, are you seeing more properties infested with Japanese knotweed? What impact does it have on the conveyancing process?