wild shrub St John’s wort?

I have a sort of wild self seeding St Johns wort shrub, grows about 4/5ft or so high with thin wood branches lovely yellow bell fluffy flowers blooming at the moment, new shoots grow all over the place. Dont know what its called. Can you identify? And if so, can you tell me if the roots smell good as my dog is digging up the garden all over the place to get down to the roots (i think) It was handy as when i wanted to remove the unwanted bushes I pulled it up easily, the roots don’t seem to go down very far. Its a lovely shrub but does spread everywhere. the wasps love it.