My favorite seed house for perennial ornamentals is Chiltern’s in the UK. I grew a packet of mixed Campanula seeds they offered and ended up with just two adult plants that survived the transition to the garden and beyond. One is a blue C. lactiflora and the other is a white version.
I’m familiar with more diminutive bellflowers. But these milky bellflowers get to be tall and full–close to four feet tall for me and probably three feet across when they are in full bloom.
I don’t have as many photos as I should of these plants, so I’ll make sure to add some new ones this year.
My 2020 plans for them are to keep them fed and watered and tied to the apple trees they are planted near.