Bellflower (Campanula) species and varieties, including annuals, perennials and biennials, come in many shapes and sizes and are among the most popular flowering plants. The name "campanula" is derived from "campana," the Latin word for "bell," and describes the feature common to the majority of campanulas--bell-shaped flowers in shades of white, blue, blue-purple and pink.
In the wild, bellflowers grow in open, sunny places like meadows, edges of fields, exposed hillsides and even in mountain rock crevices, so plant them in spots that receive five to six hours of sunlight per day. All like good drainage, but species used in rock or alpine gardens require very lean soil, amended, if necessary, with fine gravel. For traditional cutting garden types, amend clay soil with organic matter. Rock or alpine species are usually also the most tolerant of drought conditions. Since bellflowers are native to the Northern Hemisphere, many species tolerate cold winters. Check plant tags to find out whether specific types are cold-hardy in your USDA hardiness zone.
Cottage gardeners have long loved biennial Canterbury bells (Campanula medium), with their tall stems and single or double flowers. Among the most popular perennial species for cutting gardens are peachleaf bellflower (C. persicifolia), clustered bellflower (C. glomerata) and chimney bellflower (C. pyramidalis).
Though Linnaeus named the genus campanula in the 18th Century, the plants---especially those originating in Europe, the Middle East and Asia--were domesticated centuries before. Bellflowers were among the first ornamentals settlers brought to the New World and ever since they have been included in "old-fashioned" gardens. American painter Stephen Parrish, father of artist Maxfield Parrish, grew campanulas in his celebrated early 20th Century garden in Cornish, New Hampshire.
Bellflowers for Special Situations
The low-growing perennial campanulas are especially good for rock gardens, alpine gardens, the crevices in rock walls, the front of the border and edging. Species that originated in mountainous regions are the best for for these uses. They include Carpathian harebells (C. carpatica), Dalmatian bellflower (C. portenschlagiana), Siberian bellflower (C. poscharskyana) and fairies' thimbles (C. cochlearifolia).
Many of the lower-growing species also work well in pots, provided the drainage is good. Annual and biennial species, most notably C. medium or Canterbury bells, tend to reseed readily, making them almost like perennials.