Our research reveals that Japanese knotweed has inflicted a staggering £11.8 billion loss on the current value of the UK housing market. This invasive plant continues its relentless spread across the nation, making affected homes significantly harder to sell.

We estimate that roughly 4% of homes in the UK are impacted by Japanese knotweed, whether directly or through proximity to an affected property. This widespread issue is driving down property values by an average of 5%. As a result, around 890,000 households across the country are facing a typical decrease in value of £13,200 each, collectively reducing the nation’s property market by £11.8 billion.

For homeowners grappling with knotweed, the primary concern is preserving as much property value as possible. The most effective way to achieve this is through excavation of the root system. Our data indicates that both buyers and sellers are increasingly moving away from traditional herbicide treatments in favour of excavation, where the plant’s extensive rhizome system is carefully removed. This approach not only limits the decline in property values but also mitigates the risk posed by the plant. In 2021, nearly 70% of our customers chose excavation as their preferred method of treatment, marking a 10.6% increase from the previous year. Conversely, the use of herbicide treatments dropped by 17.7% over the same period.

A decade ago, herbicide was the most common method for dealing with knotweed on residential properties. However, it is now increasingly viewed by homeowners as merely a control method, rather than a cure. While herbicide can eliminate visible growth above ground, it often sends the root system into dormancy beneath the surface. This dormant state allows the knotweed to regrow, especially if the ground is later disturbed by landscaping or building work. Such concerns make potential buyers wary of the risk of regrowth, which negatively impacts property value. On the other hand, when an infestation has been professionally excavated and comes with an insurance-backed guarantee, mortgage lenders are more satisfied, and property values can be restored to near their original levels.

To further reduce excavation costs, consider a combination treatment and removal method, such as DART™. This approach removes the majority of the knotweed crowns and rhizome system, significantly weakening the plant and encouraging any remaining rhizome fragments to grow, making them more vulnerable to herbicide treatment the following spring. The excavation can be carried out during the winter months, allowing full use of your garden during the summer.

Whatever your situation or budget, we offer cost-effective solutions to your knotweed problem, helping to protect your property’s value. Contact us today to arrange a consultation.