Many perennial borders have at least one bellflower variety in them, as the family is huge and the range of plants enormous. C. glomerata, commonly called clustered bellflower, has lovely dark-purple blooms (there is also a white and blue variegated variety), but it is quite invasive.
There are bellflowers that form tufts of foliage at ground level and then send up flower stalks, like the peach-leaved bellflower (Campanula persicifolia). Also included in the family are tall varieties such as Brandford bellflower (C. latifolia).
Probably the most popular variety is a rather short version called the “Clips” series (Campanula carpatica), useful in areas where space is limited. Commonly called Blue Clips and White Clips, these plants form low, cushion-shaped mounds of fine-textured foliage of small, round, light-green leaves. They are sometimes labelled as Carpathian Bluebells as their native habitat is the Carpathian Mountains. Being mountain plants, they prefer cool summer nights and may look stressed during periods of hot summer weather when nighttime temperatures remain high.
The plants produce clear medium-blue or white (depending on the variety) up-facing, open, cup-shaped flowers during the entire summer, with the first flush of bloom in early summer. If the plants are regularly deadheaded, they will continue to bloom all season. If they begin to get leggy and only produce sporadic blooms in midsummer, some renewal pruning may have to be done. This involves cutting back a few stems at a time over a period of a couple of weeks until the plants have been rejuvenated. Some people simply shear off the top 10 cm or so of the plants, which soon recover and quickly again produce flower buds.
Blue Clips and White Clips are easy-care plants. They are not demanding about the soil or moisture, and seem to withstand dry periods quite well, although the flowers will be bigger and longer lasting if the plants have consistent moisture at their roots. Clips like full sun but will also thrive in a part-sun location. They will become less compact the more shade they must endure so for bushy, compact plants, provide them with full sun.
The plants grow only about 20 cm tall so are self-supporting. If a mature plant begins to split in the middle and fall away, simply tie a string around the plant — low enough so it will be hidden by the foliage but high enough so that it will tighten the plant up and close the gap in the centre.
Because of their small size and mounding growth habit, as well as their continuous bloom, Clips are useful plants in the landscape. They can be used as edging along the front of a perennial border. Because they are so tidy, they are often planted along sidewalks or as short foundation plantings. They are also good accent plants in mixed flower beds.
Its compact growth habit makes Blue Clips a wonderful addition to a rock garden or a container. It can be mass planted to produce a tall ground cover of blue or white (the plants should be planted closer together in this instance to create a carpet effect). Because they can withstand some drought, they can be planted to perk up a dry spot in the garden. They are perfect for those small spaces that are difficult growing areas. The open cup-shaped flowers seem to lure butterflies and hummingbirds to the plants, and surprisingly, they also make great cut flowers.
Wherever you use Campanula carpatica — whether the blue variety or the white version — it just may the perennial you need to enhance your landscape this summer.