The campanula Ringsabell series features bell-shaped flowers with a perky scalloped edge suspended from slender stems that rise above the medium-green foliage. Compact and tidy, this campanula series does not run rampant like others of its type, but spreads slowly. Ringsabell varieties provide lovely summer color in beds, borders and containers, and may rebloom in the fall.
The highest quality plants are produced by allowing the crown to fill the pot prior to bloom. This can be achieved by planting outdoors in late summer or early autumn or by planting in a cool greenhouse in late winter or very early spring.
Use a well-draining potting soil containing a slow-release, low- to medium-rate fertilizer charge, or provide a balanced liquid feed with 200-ppm nitrogen while plants become established. Withhold feed as cold weather sets in to harden off plants for winter. Resume regular feeding when new growth emerges in spring.
Plant the crown at soil level, no deeper, or problems with crown rot could develop. A preventive fungicide drench at transplant is recommended.
Pest problems are few, but watch for aphids, thrips and mites during the growing season.