Japanese knotweed the pervasive plant

As biologists conduct their fieldwork, they encounter knotweed colonies that rival the size of double-decker buses. One expert from Wales vividly recalls stumbling upon a colossal stand of knotweed sprawling over an astonishing 20,000 square meters, almost equivalent to four Boeing 747s parked side by side. Knotweed's audacious invasion even impacted the preparations for the 2012 Olympics, necessitating a staggering £70 million expenditure to cleanse affected venues of the pervasive plant.

Traditional methods of eradication fall short in the battle against Japanese knotweed. While lawn moss can be vanquished with iron sulphate and nettles can be plucked from the ground, knotweed proves nearly indomitable. It resists complete annihilation, surviving defoliation, mowing, and uprooting. Poison may temporarily control its growth, but the plant's resilience makes it challenging to eliminate. Knotweed's rigidity is so extraordinary that it has been compared to the fictional triffids from John Wyndham's novel, "The Day of the Triffids." However, instead of posing a physical threat to humans, knotweed inflicts economic harm by devaluing properties.

The impact of knotweed on property values cannot be underestimated. In an era where housing wealth often constitutes a significant portion of personal wealth, the presence of knotweed can lead to substantial financial losses. It is estimated that around 5% of homes in the UK suffer from knotweed infestation, potentially reducing their collective value by a staggering £20 billion.

To address this issue, property selling forms now explicitly inquire whether the property is affected by Japanese knotweed. Failing to disclose this information can have severe consequences. In a recent case, a court ordered a man to pay £200,000 in damages after he sold his London home for £700,000 without acknowledging the knotweed infestation in his garden.