This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
The genus Campanula is extraordinarily rich in flowering garden plants of merit. The alpine section is distinguished by a charming grace both in character of growth and size and bearing of flowers. The peach-leaved class (C. persicifolia) is characterized by the noble and beautiful form of single and semi-double blossoms carried by thin erect stems 2-3 feet high. The luster and clearness of tints of the bushy biennial Medium and calycanthema type are remarkable, while the rambling habit and the marvelous floriferousness of the varieties C. isophylla and its descendant C. Mayii, indicate the wide range of ornamental usefulness of bellflowers. Considering the good lasting qualities in a cut state and the great popularity of the flowers of long-stemmed sorts for indoor decoration, it is safe to say that campanulas will steadily gain in importance as material upon the florists' counter as well as for garden planting. The greatest curiosities are C. punctata, C. macrostyla, C. Zoysii and C. rotundifolia variety soldanellaeflora. For exhibition and for pot culture and also for large single specimens, C. pyramidalis is most used. For edgings, C. carpatica is perhaps the favorite.
Of all wild forms, the best known is certainly C. rotundifolia, the true harebell, or "blue bells of Scotland." It is native in North America as well as in Europe, on rocky banks and shores. -Wherever rock-gardens are planned, alpine campanulas have become indispensable. The greater part of typical mountain inhabitants chiefly available for this purpose being spring-flowering plants, the summer flowers of campanulas are especially welcome. One of the best bellflowers for rock-gardens is C. carpatica, blue and white, with its variety compacta also in blue and white, variety caelestina, sky blue, variety pelviformis, light blue, and variety Riverslea with large dark-blue bells; but there are a number of other very handsome species possessing commercial value that deserve the attention of progressive growers. The demand is for a plant material easy to handle, resistant and free-flowering. As such may be recommended for rockeries, C. gargan-ica and C. garganica variety hirsuta, both 4 inches high, flowers light blue. C. pusilla, in white and blue, is regarded as the hardiest low-growing alpine bellflower.
Excellent effect may be secured from a number of the garden hybrids, when rightly employed; plantations of C. Wilsonii, cross between C. pulla and C. turbinata, dark blue, 6 inches tall, and C. Fergusonii and C. Hendersonii, 12 to 18 inches, all blooming freely from late in June to early August, are good examples. Campanula glomerata variety acaulis, a clustered-flowering low-growing form, violet-blue, June and July, answers the same purpose, while C. glomerata variety dahurica, 12 to 18 inches, dark violet-blue and white, very free-flowering, is valuable also as a border plant. Other good rockery kinds are C. fragilis (which needs protection, but makes a good pot-plant), C. pulla in sheltered position, C. Portenschlagiana, and C. rotundifolia. Many of the larger-growing kinds are also good for the rock-garden. -The best two representatives of the biennial class, are C. Medium and C. calycanthema, both standard garden flowers. In the northern states, especially, they do exceedingly well. When used for mass effects, their full bloom becomes a prominent feature of June. The delicate shades of pink and pale lavender, the purity of the white, and the rich tints in purple and blue are a revelation.
They transplant very easily, even in an advanced state of growth, and readily respond to mild forcing under glass in spring. In a cut state, they show remarkably good lasting qualities and are of excellent value as material for filling vases. A few other good biennials are C. sibirica, C. primulaefolia, C. spicata, (p. 650), C. thyrsoides. - The peach-leaved section comprises the most perfect forms of the bellflower family, although C. persicifolia has been surpassed in popular favor by the more vigorou C. grandiflora varieties in white and blue, which are really platycodons. C. isophylla, native of Italy, is not hardy in Maine and must be overwintered under glass. It is a very effective basket- and balcony-box plant, its Jong hanging vines being covered with large and attractive flowers in July and August. The color is a delicate light blue, while the bells of its garden descendant C. Mayii, have a deeper shade. For the South, both are valuable acquisitions for rockeries. - Of the perennial species, according to Robert Cameron, the best border plants are the following: C. carpatica and vars. alba and turbinata; C. glomerata, especially variety dahurica; C. lactiflora; C. lati-folia, especially its vars. eriocarpa and macrantha; C. nobilis (about 2 ft. in height); C. persicifolia and its numerous vars., especially the white kinds; C. punctata (about 1 1/2 ft.); C. pyramidalis, a very showy plant when well grown, but not quite reliable in the eastern states as to hardiness, making a good pot-plant for the cool greenhouse; C. rapunculoides, which spreads rapidly and must be so placed that it will not crowd out the other plants that are near it; C. rotundifolia; C. Trachelium; C. Van Houttei, a hybrid, and one of the best bellflowers. - Campanulas are raised from seed and also by division or cuttings.
Seeds should be started early under glass. Cover very shallow, and place the shallow seed-pans near the light in an average temperature of 60°. Shade at midday while in process of germinating; avoid over-watering and "sticky" atmosphere. Transplant seedlings into flats as soon as they can be handled. Harden young plants gradually and transfer them to the open ground in May. C. Medium, C. calycanthema, and all the C. persicifolia varieties, when grown for the cut-flower trade, should be placed on beds where they are intended to be flowered and cropped the next season. They thrive best in a rather light well-manured garden soil. Some of the alpine species require a sandy humus with additions of fine limestone material. When grown for floral garden effect, the open sunny position is preferable throughout the North, while for the South half-shade at midday is likely to prolong the flowering season. Seedlings of single varieties come true to color to a high percentage. Of the semi-double and double C. persicifolia sorts, propagation is usually by division in September. C. isophylla and C. Mayii are shy seeders and are propagated by cuttings in spring.
For winter protection, a light covering of straw, leaves or evergreen boughs is sufficient south of New York. In more northern parts, hardy campanulas require a uniform layer of leaves 2 to 3 inches thick. The annuals can be raised in the border by seeds sown late in April or May, or raised in the greenhouse and then transferred to the border. The best of the annuals are C. ramosis-sima and variety alba, C. drabifolia, C. Erinus, C. macro-styla, and C. americana. (Richard Rothe.)
C. primulaefolia and C. spicata will be found in the supplementary list, p. 650.
1. Rapunculus, Linn. (Rapunculus verus, Fourr.). Rampion. Fig. 763. Biennial or perennial, 2-3 ft.: root spindle- or long-radish-shaped, 1/2in. thick, white: stem erect sulcate: lower leaves obovate, short-petioled, somewhat crenate; stem - leaves linear-lanceolate, entire: flowers calyx-tube obconical, lobes lilac, in a spike or raceme; glabrous or bristly, erect, awl-shaped, a half shorter than or nearly equal to the funnel-shaped corolla. Eu., Orient, N. Asia, N. Africa - The roots and leaves are eaten as a salad. The seeds, which are very small, are sown in the open ground in early May either broadcast or in drills. A little sand mixed with the seed gives an evener sowing. Press firmly, and water carefully. Thin out the seedlings if necessary. Water freely in hot weather. A fresh sowing may be made in June, as early - sown plants may run to seed. Roots are gathered in Oct. and may be stored in sand for winter use. "Rapunculus" means a little turnip.
Fig. 763. Root of rampion-Campanula Rapunculus.