Japanese Knotweed according to the Environment Agency is the most invasive species of plant in Britain. The current law is that landowners must be proactive in destroying the plant. Although you are not legally obliged to remove the weeds or indeed to control them, you could be prosecuted if you allow Japanese Knotweed to spread onto a neighbour’s property.
Over £160 million is spent every year in the UK on Knotweed control. The plant is bamboo like in appearance and produces white flowers in the late autumn. The leaves are dark green and heart shaped making it quite distinctive.
If you are concerned about Knotweed there are specialist firms who can help for further information visit https://www.gov.uk/guidance/prevent-the-spread-of-harmful-invasive-and-non-native-plants