Vast and varied group (nearly 300 species) encompassing trailers, creeping or tufted miniatures, and erect kinds 16 ft. tall. Native throughout the Northern Hemisphere; species described here are perennials mostly from southern Europe, Turkey, the Caucasus, and northern Asia. Flowers are generally bell shaped, but some are star shaped, cup shaped, or round and flat. Usually blue, lavender, violet, purple, or white; some pink.
Uses are as varied as the plants. Gemlike miniatures deserve special settingsclose-up situations in rock gardens, niches in dry walls, raised beds, containers. Trailing kinds are ideal for hanging pots or baskets, wall crevices; vigorous, spreading growers serve well as ground covers. Upright growers are valuable in borders, for cutting, occasionally in containers.
In general, campanulas grow better in good, well-drained soil and the cooler climates of the Upper and Middle South. Most species are fairly easy to grow from seed sown in flats in spring or early summer, then transplanted to the garden in fall for bloom the following year; also may be increased by cuttings or divisions. Divide clumps in falltypically every 3 or 4 years, though some may need yearly division.
C. carpatica. TUSSOCK BELLFLOWER. Forms compact, leafy tufts with branching, spreading stems. About 8 in. tall but may reach 1112 ft. Smooth, bright green, wavy, toothed leaves, 1112 in. long. Single blue or white flowers to 12 in. across are upward facing, bell or cup shaped. Blooms in late spring. Use in rock gardens, borders, edging. Not browsed by deer. 'Blue Clips' ('Blaue Clips') and 'White Clips' (C. c. alba 'Weisse Clips') are good dwarf selections that are easily grown from seed; they are sometimes sold as 'Blue Chips' and 'White Chips'. 'China Doll' is a 6-in.-high selection with pale lavender-blue flowers.
C. glomerata. CLUSTERED BELLFLOWER. Upright, with erect side branches to 12 ft. Leaves are broad and somewhat hairy, 24 in. long; basal leaves are wavy edged, stem leaves toothed. Narrow, bell-shaped, 1-in.-long, blue-violet flowers are tightly clustered at stem tops. Summer bloom. Plant in shaded borders. Seed-grown strains Superba and Alba are deepest purple and white, respectively. 'Caroline' is lavender. 'Joan Elliott' is deep violet-blue. 'Purple Pixie' has violet-purple flowers on 14-in. stems.
C. lactiflora. MILKY BELLFLOWER. Erect, branching plant to 3125 ft. tall. Oblong, toothed leaves, 23 in. long. Broadly bell-shaped to star-shaped, 1-in.-long, white to pale blue flowers in drooping clusters at ends of branches. Summer bloom. Plant in back of borders in sun or partial shade. Endures even dry shade and is long lived. 'Loddon Anna' has pale pink flowers. 'Pouffe' (lavender) and 'White Pouffe' form a 10-in. bloom-covered mound.
C. persicifolia. PEACH-LEAFED BLUEBELL. Graceful, strong-growing plant with bright green foliage. Narrow basal leaves, 48 in. long, form a low clump to 112 ft. wide. Slender, erect, leafy stems rise 23 ft. high in summer, in loose spires of open, cup-shaped, inch-wide blossoms of blue, pink, or white. Choice plants for borders. Easy to grow from seed sown in late spring. Longtime favorite 'Telham Beauty' has 3-in. blue flowers. 'La Belle' and 'White Pearl' have double flowers. 'Chettle Charm' has white flowers softly edged with lavender. 'Takion White' and 'Takion Blue' are heavy blooming and compact at 18 in. tall.
C. poscharskyana. SERBIAN BELLFLOWER. Vigorous grower forms a spreading mound to 8 in. high, 2 ft. wide. Mid-green leaves are an elongated heart shape, to 3 in. long and 3 in. wide. Branching, semiupright flower stems reach 1 ft. long or more, with star-shaped, 1-in.-wide flowers in lavender or grayish white. Blooms from spring to late summer. Needs only moderate water; good ground cover for dryish shade. 'Alba' has white flowers. 'Blue Waterfall' ('Camgood') has light blue flowers with white centers. Remove spent flower stems with a gentle tug to prevent reseeding.