She should have read last year's article (or her neighbour and the council should have read it): UK government concedes defeat to Japanese knotweed. I see that one can buy insurance to cover the discovery of Japanese knotweed on a property in England: Japanese Knotweed - Countrywide Legal Indemnity Cover The CBC reports that we're using goats on it in nearby Chilliwack (reported in May, 2016) Goats turned loose on Chilliwack's destructive Japanese Knotweed I wonder what we're doing here about the knotweed at the base of the Ironworkers Bridge? Concrete-busting weed can threaten projects
Over several years, I eliminated a fairly small stand of Japanese knotweed in my Burnaby, BC garden by constantly keeping it cut off at ground level. This method also worked on goutweed, lily-of-the-valley and chameleon plant. All were completely on my property . . . not coming in from the neighbour's. It requires great vigilance and patience but is eventually successful. Most plants do need to photosynthesize to live.