@greenfingers steve Hi there, Steve, yes, you're right, I've finally remembered to check the aggressive smoke bush and it is indeed Grace (Dummeri). Just going completely wild and taking over the bed!
Coppice it (cut it down to the ground in spring) ... you'll get bigger leaves, better colour and you'll be in control.
Posts
https://www.telegraph.co.uk/gardening/howtogrow/3345300/Smoke-bush-How-to-grow.html
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.