How bleak would Britain appear in many places without the most loved and at the same much hated Buddleia davidii!
It was brought over originally from China and the seeds are now everywhere. You do have to spot them early in built walls to prevent damage. It is always wise to keep your drain pipes clean so they can not germinate in there.
Buddleias are much loved by many butterflies and for me personally water infused with Buddleia flowers makes for lovely fragrant water to splash your face with first thing in the morning.
Buddleias are hardy and versatile and a valuable resource of dry wood.
These days there are many hybridised garden varieties on sale such as the beautiful weeping Buddleia alternifolia, if you do not want to dare to let one grow where it has germinated, apart from on your garden wall of course.