Japanese knotweed is a herbaceous perennial native to Japan, China and parts of Korea. It was introduced to the UK in 1825 by German botanist Philipp Franz Balthasar von Siebold, who was unaware of the devastating impact it would have. According to the RHS, Japanese Knotweed has "bamboo-like stems which grow to 2m (6.5ft) tall”. Aggressive and fast-growing, the plant can grow up to 10cm a day and is classed as ‘controlled waste’ under the Environmental Protection Act 1990.
