Flower description / bloom time
Large, 2 ½ inches long, dark purple, bell-shaped flowers appear heavily in June for about two weeks, and then smaller flowers appear sporadically through August.
Foliage interest / color and texture
Small heart-shaped leaves are medium green and a medium texture, which stay healthy all year long.
Habit and growth rate observations
Sarastro is a cross between Campanula punctata and Campanula trachelium and is 18 to 20 inches tall with an equal spread. The growth rate is slow and by underground rhizomes.
Site preference / soil and light
The most successful plantings were in moist, well-drained soils with supplemental watering and a light mulch. These received morning sun and afternoon shade. Some plants sited in full sun died the first year.
Successes and possible drawbacks—how to overcome them
The positives reported for Sarastro were the showiness of the flower and stems that remained more up right than Campanula ‘Kent Belle’. Cutting the plant back after first bloom rarely resulted in a good second flush of growth.
Notes from growers / retailers
While easy to grow in pots, the plant does not have much eye appeal in containers, unless it is in bloom.
The dark purple flower color will combine nicely with soft pastel colors such as pink, lemon yellow, and white. Some suggestions included Achillea ‘Moonshine’, Iris sibirica ‘Gull’s Wing’, Geranium sanguineum ‘Album’, and Geranium ‘Ankum’s Pride’.
Parting SHOT —the overall evaluation results were Fair to Poor *
The Evaluation Team did not recommend this plant, as the overall rating was Fair to Poor. The showy flower display in June was rated good to excellent, but problems with vigor and hardiness brought the ratings down. In our study, only 65% survived the three years. It did stay more upright than Campanula ‘Kent Belle’, but still needed some support during its heavy bloom period.