Campanulas

Peter Lewis writes on good varieties which deserve to be grown more widely.

Campanulas, the bellflowers, are old garden favourites. Massed in the midsummer sun of the cottage garden, one may almost hear them chiming in the breeze. But, apart from the few which most gardeners recognise, like the Canterbury Bell (Campanula medium), Fairy Bells (C. cochlearifolia), the Scottish Bluebell (C. rotundifolia) and the blue or white C. isophylla, frequently grown in baskets in windows, although none the less hardy for that, it is not generally appreciated how easy and rewarding the campanulas can be. The lists of the specialised societies apart, the range offered as seed is at present limited.

The primary aim of the National Council for the Conservation of Plants and Gardens is to locate and rescue plants, both species and cultivated varieties, which are in danger of being lost to cultivation. Those of us who have the care of the National Collections see several roles ancillary to this, one of these being to renew acquaintance with types which have been neglected, perhaps for generations and probably quite undeservedly, and to assess and record their worth in gardens today.

In a recent article Graham Pattisson drew attention to several beautiful campanulas which have become rare in cultivation (and which are not common in the wild either!). The biennials C. celsii, C. lingulata, C. miribilis and C. primulifolia are among these. They and many others come from areas with more favourable climates than the average British garden, but then so do many other plants which we grow successfully. We have in recent years proved that, given conditions which take into account these origins, most plants will come through both winter frosts and summer droughts which may be different from those of their native environment. This is often a matter of no more than the good drainage of the beds we put them in.

Here are a few more which are easily raised from seed and should be more widely grown.

Campanula abietina. A variant of the British C. patula; happy and worthwhile at the front of any border; biennial or short-lived perennial.

Campanula betulifolia. Soundly perennial in border or rock garden; pinkish-white flowers above the birch-like leaves that give it its name.

Campanula collina. A perennial with 12in (30cm) high deep violet bells.

Campanula incurva. From Greece, but a quite hardy biennial; forms a basketwork of pale blue or cream bells of good size and long lasting.

Campanula kemulariae. Front-of-border perennial; bright green leaves forming a 2in (20cm) mound topped by pale cream bells.

Campanula raddeana. Leaves similar to the above, but with 12in (30cm) reddish stems bearing deep violet hanging bells.

Campanula nitida. A miniature form of the well-known C. persicifolia, the flowers being full size. Seed gives a proportion of tiny plants which may easily be separated when quite small.

Campanula rupestris. A beautiful rosette until it flowers, then dies. Deep blue bells line the stem; appreciates shelter, but we grow it in the open in gritty soil.

Campanula tridentata. Large open cups of deep blue with white eye; early, and soundly perennial on rock garden or in pot; 8in (20cm).

Campanula thyrsoides. A 20in (50cm) curiosity spike of yellow clustered flowers.

Most seed companies offer perhaps a half dozen sorts of campanula. A good specialist grower may offer twenty-five varieties. We have in cultivation over 250 variants of the genus; apart from those which are real plantsman's subjects, or a downright challenge, there is a great number which could 'ring the changes' in many a garden.

Peter Lewis is custodian of the National Collection of campanulas under the auspices of the National Council for the Conservation of Plants and Gardens.

Source of article
Growing From Seed - Autumn 1987 Vol. 1 Number 4
© The Seed Raising Journal from Thompson & Morgan