One knot to sing about, another a noteworthy must-have

Brought home by plant-hunters from far-off Japan, it won prizes and to the delight and genteel hand-clapping of lady gardeners of that era, was retailed to the public.
Gardeners, district councils, builders, and developers have since had cause to regret that enthusiasm. As we know, Japanese knotweed is a curse to which there has been, so far, no long-term solution. Local authorities, after ignoring it for years, are making efforts to control it. In West Cork, I see roadside stands treated with herbicide here and there. The National Biodiversity Centre has assisted the authorities. The Irish Examiner has repeatedly published articles highlighting the need for action.