Do you have Campanula persicifolia var. planiflora ‘Coerulea’ currently in stock at the nursery?
They are fully to half hardy and are grown in the sun or shade. Most of the species will prefer moist but well drained soil. Delicate flower colours are preserved best in shade.
You will need to sow the seeds in a cold frame in the spring. divide in the spring or the autumn.
Pests, diseases or disorders
Watch out for aphids and scale insects under glass, also slugs and snails.