Campanula medium, with the common name of Canterbury bells, is annual to biennial plant. The first year from seed you get a rosette of leaves but no flowers, unless there is a very long growing season. In the second year they produce lots of pretty, bell-shaped flowers in colors of blue, pink and white. Then they go to seed and die. If allowed to reseed themselves gardeners will get a good show every other year if you don’t weed out the non-blooming plants the year they sprout. Blooming time is June-July.
― John Lubbock, The Use Of Life