Alert as Japanese Knotweed spotted earlier than usual

There’s a claim that Japanese Knotweed, described as one of the UK’s most invasive plant species, has been spotted growing earlier in the year than usual.

Adam Brindle of the firm Japanese Knotweed Specialists suggests that early signs are bad signs, as the plant has an aggressive growth habit of up to 10cm a day in the summer.

He says typically, the first signs of new growth are expected in Spring, when purple shoots start to emerge between April and May, before turning into bamboo-like pillars and reaching a higher rate of growth by June.

When Japanese knotweed has matured it becomes identifiable through its hollow canes, creamy white flowers in late summer, heart shaped leaves, and zig-zagging growth habits.

Companies involved in treating it claim that as many as 1.45m homes in the UK alone could be affected by knotweed infestations. 

Brindle, who spotted the early infestation in an unspecified part of the south east, says: “Whilst we expect to see Japanese knotweed emerge as early as April, sometimes May, we’re seeing red flags that infestations could be developing much sooner. The problem with knotweed is how aggressively it grows, which can puncture through cracks and other vulnerabilities in concrete. 

“At its worst, knotweed has the strength to destabilise a property’s foundations, which is what we aim to prevent. To stop it, make sure you seek the help of an expert.”