Am I missing something? This is Nunhead station in south-east London. Down the left, where old buildings along the platform have been demolished, there is a thicket of buddleja (buddleia if you like). Down the right, along the trackside, is a sea of Japanese knotweed.
The one is lauded as a valuable and important nectar source for bees and butterflies. The other is derided as a noxious invasive weed. Neither, in my opinion, has any part to play in nature, wildlife, or biodiversity.
The buddleja on Nunhead Station was being visited by one queen bee. One. This is the truth about buddleja. It is a waste of space, an invasive thug of a plant, a crowding shading useless shrub with virtually no value to wildlife.
Gone are the ox-eyes and St-John’s-worts, the hawkbits and wormwood and all the other lovely brownfield flowers that ARE so important. Buddleja, boo I say.
Richard Jones
Bugman Jones 
Don’t worry, the local authorities are probably doing their utmost to destroy “injurious” weeds like ragwort instead!