Japanese knotweed, also known as Fallopia japonica or Polygonum cuspidatum, is a non-native plant introduced by Victorian plant hunters in the mid 19th century.
Its popularity grew because of its ability to grow quickly, forming dense screens. However, this characteristic meant it could out-compete indigenous species and it quickly became a problem.
Plants were still being sold though until the early 20th century and it can now be found across the country.
