Lord Greaves – 2014 Parliamentary Question to the Department for Environment, Food and Rural Affairs

The below Parliamentary question was asked by Lord Greaves on 2015-01-14.

To ask Her Majesty’s Government what assessment have they made of the rate and extent of the spread of Japanese Knotweed in the United Kingdom and other parts of the world where it is not native.

Lord De Mauley

We are aware that Japanese knotweed is widespread across many parts of the world; recent information (from the CABI Compendium, part funded by Defra) suggests it is found in 35 countries outside its native range. Following its introduction to the UK in the early 1800s, Japanese knotweed was first recorded in the wild in 1886. Its initial spread was slow. By 1930 it was present in 73 hectads (i.e. 10km x 10km squares) in the British Isles; by 1986 it had spread to 948 hectads and it is now present in approximately 2,879 hectads.