Rosebay willow herb

This plant grows everywhere: on every road verge; abandoned factory; piece of disturbed ground; along the canal tow paths or railway sidings - I mean everywhere. I quite like the pretty pink flowers, but hate the white cottony seeds as they make me sneeze and wheeze. Last year I let them flower in my front garden and then pulled them up before the seeds developed - or so I thought! Some must have survived, or others flew in, as I have another ready crop this year. These will be removed also, but I suspect more will be back to replace them.