Campanulas are native to the northern hemisphere, from The Pyrenees, through the European Alps, the Mediterranean countries, to the Caucasus and Russia, where they grow in high pastures, woodland, mountain crags and scree. North America, North Africa and the Himalaya are home to a number of species. Campanula rotundifolia, our native harebell, (the ‘bluebell’ in Scotland) grows wild in its many forms in more regions than any other bellflower, from sub-arctic  zones, throughout Europe, into Asia and North America.

A Brief History...

Since the late 16^th century, botanists and planthunters have sought to identify and catalogue the huge genus that is Campanula.  In 1597, the herbalist John Gerard refers to Campanula medium (Canterbury bells) and Campanula trachelium (Bats in the belfry), used to treat throat infections.  European collector Alphonse de Candolle produced the first work on campanulas in 1830, and Henri Correvon popularised bellflowers in The Garden in 1901. Reginald Farrer was an avid alpine Campanula collector, often himself baffled by the number of species he found growing in the Alps. In his 1918 The English Rock Garden, he advises the ‘necessity of weeding the many beautiful sheep from the many goats in the family.’ H. Clifford Crook wrote his monograph in 1951, a dated but invaluable reference work for Campanula enthusiasts, and in 1953 in the United States, Dr Liberty Hyde Bailey published his Garden of Bellflowers in North America. Top nurserymen, such as Walter and Will Ingwersen at Birch Farm and Alan Bloom at Bressingham, added new species and cultivars to their catalogues in the twentieth century.

Descriptions

The best known of the genera in the Campanulaceae family, Campanula, or bellflowers, comprise some 400 species of annuals, biennials, perennials and monocarps, as well as ever-growing numbers of cultivars and hybrids. The list of species originating from mountainous regions is extensive and diverse, from the miniatures, such as Campanula cochlearifolia AGM (fairy thimbles) to the more robust, C. portenschlagiana AGM.  There is a choice of over 200 alpine forms listed in the RHS Plant Finder alone, many with the RHS Award of Garden Merit.  Sadly, even in the last decade, a significant number of entries have disappeared, including Campanula carpatica cultivars with evocative names such as ‘Harvest Moon’, ‘Queen of Sheba’ and ‘Claribel’.

Generally flowers are borne on single stems rarely exceeding 6” (15cm) in height. The bell- or star-shaped flowers are mostly blue, purple or white, with some pink variants and one yellow, C. thyrsoides. Many will show a tufted or creeping habit, clinging to rock or the edge of a dry wall or container. Some are considered weeds; for instance Campanula poscharskyana has an invasive nature, although its cultivars are less thuggish – bright blue C. poscharskyana ‘Stella’ AGM and pinky-lilac C. p. ‘Lisduggan Variety’. 

Cultivation

Most Alpine Campanula are easily pleased in an open position in sun or partial shade. However, SHARP DRAINAGE is vital for successful cultivation. They require free-draining and not overly rich soil, and, with a few exceptions, are lime-lovers. Whilst the majority withstand extremes of temperature, they dislike prolonged winter wet.  For best results, copy the conditions nature supplies in the wild. High in the mountains, alpine campanulas encounter drought during spells of parching summer.  They have adapted to this by sending down long roots for moisture and nourishment from below ground. Be sure to add ample grit and a trowelful of John Innes No 3 when planting.

From early summer until beyond the first frosts, alpine campanulas add colour and interest to the rock garden, border and container.  Many give a late show if trimmed after their first flowering, for instance Campanula carpatica AGM and its cultivars.  The range and flowering season can be extended by growing  more challenging varieties under glass, eg Campanula ‘Joe Elliott’ AGM, and the woolly-leaved forms, such as Campanula formanekiana AGM.

Propagation

Seed from species bellflowers is generally plentiful. Members of the Alpine Garden Society and Scottish Rock Garden Club benefit from annual seed distributions, which contain many interesting species. Sowing is recommended in winter, when exposure to frost will aid germination, in a gritty compost and a dusting of grit over the seeds. Often these are tiny so mixing with dry sand will help even distribution.  Campanulas germinate better in the light, preferably in a cold frame.  Alternatively, plants can be divided in spring or cuttings taken.  Both means of vegetative propagation are essential for named cultivars.

Why grow alpine campanulas?

With such a wide range of forms in one single genus, there is an alpine Campanula for most garden situations, from rock and scree gardens, to wild and woodland areas.  I have been collecting campanulas for seven years, inspired by Peter and Susan Lewis, Collection Holders for 25 years. They taught me how easy it is to become an obsessive Campanula collector. Beware!

© Sue Wooster