Homeowners are being advised to be on the lookout for Japanese knotweed on their property, which has appeared six weeks ahead of schedule this year due to unusually warm weather. These distinct red stems were noticed in February and March, which is likely a consequence of climate change.
Dealing with this highly tenacious plant is costly, with the expense running into hundreds of millions annually. If knotweed is found on a property, owners can face hefty treatment costs that may last for years and negatively impact the value and marketability of their property.
England and Wales experienced the warmest February ever recorded this year, characterized by mild and wet conditions. The Property Care Association (PCA), a group of building professionals, observed that this climate allowed the knotweed to flourish much before its typical growing season in April.
Ben Lindley, a specialist in eradicating Japanese knotweed, has pointed out that the plant tends to break through earlier in warmer conditions. He has seen a surge of growth starting from February and March, which is about a month to a month and a half before they usually appear.
Growing Worries
The idea of having Japanese knotweed on one’s property can be unsettling for homeowners, as it’s known for causing damage to driveways, patios, and competing for nutrients and sunlight with other plants, thus hindering their growth. It also spreads rapidly, adding to the concern over its removal costs.
Initially brought to the UK in the mid-19th century for its decorative appeal, it now costs nearly £250 million a year to manage as it populates roadsides, riverbanks, and abandoned spaces. This stubborn plant can grow in various soil types.
Lindley explains that if knotweed emerges before native plants, it can overtake them by blocking their sunlight. It grows fast, potentially five inches a day, reaching over a meter tall in just four weeks.
What you see above ground isn’t the whole problem; the rhizomes beneath the surface can extend over a much larger area. They can travel from one property to another, causing distress if disturbed, prompting more growth.
Consequences
People selling their homes must legally disclose whether the species is present on the property. Giving incorrect information can lead to legal repercussions, as can allowing the knotweed to spread to adjacent properties without proper management.
In a 2019 case, a homeowner was awarded £50,000 in damages from his surveyor because the knotweed significantly restricted the use of his property.
With the appearance of knotweed now beginning earlier in the year, heightened vigilance is necessary. Daniel Docking from the PCA’s invasive weed control group advises those who spot it to seek professional help promptly to tackle the issue effectively.
Treating the Issue
Eradicating knotweed can be a protracted and expensive affair. Using herbicides over a period of two to three years is a common, yet slow, treatment method, typically costing £2,000 to £3,000. Excavation offers a quicker solution but is significantly more costly, escalating to between £5,000 and £15,000, particularly for terraced homes where accessing the site is challenging.
The Property Ombudsman reports that knotweed can cause property sales to collapse. Moreover, under consumer protection regulations, estate agents must inform potential buyers about the presence of knotweed.
Sellers are required to present a management plan for the weed, which is also a requirement for mortgage lenders.
Homebuyer Disappointed by Legal System
Purchasing a property unaware of the existence of Japanese knotweed can create legal headaches. Jonathan Rolande, a property investor, bought a home in Wales where a surveyor initially indicated the absence of the plant.
However, a later inspection found knotweed in the garden, and legal efforts to recover costs were abandoned due to the high expense involved.
“We tried to hold the surveyors accountable but got nowhere,” Rolande says, even though the survey form had indicated no presence of knotweed. Ultimately, he had to bear the treatment cost, which was around £3,000.
