Japanese knotweed

There are a couple of stands of Japanese knotweed at our nearest Local Nature reserve. Over the past ten years or so the council have religiously sprayed herbicide twice a year in an attempt to eradicate this supposedly noxious invader, although its ecological impacts are limited and it has never shown any real signs of spreading. This year no management has taken place, perhaps a sign of budgetary cuts. The Japanese knotweed has responded to this lapse by growing back even more vigorously and has produced the most glorious display of white flowers. For the first time I can understand why the Victorians might have wanted to grow this in their gardens!