asked Her Majesty's Government:
What information they have on the occurrence and rate of spread of fallopia japonica (Japanese Knotweed) in the UK: what plans they have for combating this spread; and what action is currently in hand to bring these plans to fruition.
§ Baroness Hayman
Japanese Knotweed is thought to be widespread in the UK. However, there is no centralised up to date information on the current distribution and rate of spread of this species.
It is listed on Schedule 9 of the Wildlife and Countryside Act 1981 and is covered by Section 14. This makes it an offence for private landowners and local authorities to plant, or otherwise cause to grow Japanese Knotweed in the wild. We have no additional plans to combat this species.