Common Name: bellflower
Type: Herbaceous perennial
Family: Campanulaceae
Zone: 4 to 8
Height: 1.50 to 2.00 feet
Spread: 1.50 to 2.00 feet
Bloom Time: June to August
Bloom Description: Deep blue
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Flower: Showy
Tolerate: Deer
Culture
Easily grown in average, medium, well-drained soil in full sun to part shade. Prefers part shade in hot summer climates. Does not do well when night temperatures do not consistently cool down below 70 degrees F. Needs regular moisture. Plants may be cut back to basal foliage after bloom. Divide clumps in fall every 3-4 years. Spreads freely by rhizomes under optimum growing conditions.
Noteworthy Characteristics
Campanula is a genus of about 300 species of annuals, biennials and perennials from throughout temperate regions of the northern hemisphere found from alpine areas to meadows and woodlands. Many make excellent garden plants.
Genus name comes from the Latin campana meaning bell in reference to the bell-shaped flowers.
‘Sarastro’ is a clumping, hybrid bellflower (reportedly C. punctata x C. trachelium) noted for producing deep blue bell-shaped flowers on slowly-spreading, compact plants that typically rise to 20-26” tall and as wide. Large, shiny, tubular flowers (to 2.5” long) are deep blue to purple blue. Flowers droop from leafy stems over a long mid to late summer bloom. Stems rise up from basal rosettes of medium green leaves.
Problems
No serious insect or disease problems. Can be mildly spreading. Watch for slugs and snails.
Uses
Borders, rock gardens, cottage gardens, lightly shaded woodland settings or naturalized areas. Group or mass for best effect.
Effective ground cover. Strong stems make this a good container plant.