Description from Annie's Annuals & Perennials
Campanula medium 'Deep Blue' – “Canterbury Bells”
This is the beautiful, biennial, old fashioned heirloom “Canterbury Bells.” It lacks the “saucer” of the more familiar “cup and saucer.” Introduced to England from Spain in 1596, it is a popular cottage garden flower. Growing to 30” tall with a 15” spread, it makes lotsa large, blue, flaring bells, 2” long or more on branching stems. So showy, even just one plant by itself or mingled in, mid-border. It blooms in Spring thru early Summer and loves rich, loamy soil. Reseeds!