I bought a packet of mixed species seed several years ago Lawrence, they had a bed almost to themselves but some self seeding Geraniums are taking over. The Campanula got their own back as several have self set in other places, they work it out between themselves.
I managed to recognise most of the species I had, some have disappeared. None had quite the same young leaves as your plant has but I had one which looked like C. takesimana. Campanula are a favourite plant of Megachile willughbiella which I get every year, I also found another dead bee species which is quite small and fairly rare but haven't seen a live one, I would have to search my photos for the name but it specialises on Campanula.
