All the foregoing are perennials, but two little hardy annual Campanulas are Attica and A. alba, growing about six inches high. They make useful foreground plants, and are quite at home in rock gardens. Sow in April on light soil.
The Canterbury Bell has already been alluded to; it is a charming hardy biennial forming a valuable feature of the mixed border. The large semi-double blooms of the Cup and Saucer class and the double varieties are modern introductions which have become extremely popular; the range of colours now includes the most delicate shades of pink, mauve, and blue, in addition to pure white. Seed may be sown from April to July. When the seedlings are large enough transplant them where required for flowering in the summer of the succeeding year. But Canterbury Bells are also interesting in the greenhouse during spring; for this work pot them in October and on to December. So treated, they bloom even more generously than in the garden. There can be no more beautiful adornment for a hall or large drawing-room than a well-placed group of the fine white flowers, backed by a mass of dark-foliaged plants.
Indian Shot. Half-hardy perennial
Cannas have ceased to be regarded simply as sub-tropical foliage plants, adapted only for the adornment of beds and borders. They have not lost their merits for this purpose, although in all probability the taller forms will be less grown than formerly, because the new dwarf varieties, which maintain a high standard of beauty in the foliage, include a diversity of rich tints previously unknown, and they possess the additional merit of producing flowers that have lifted the race into prominence as brilliant decorative subjects for the garden and the greenhouse.
The popular name is descriptive of the seed, which is almost spherical, black, and so hard that it has been used in the West Indies instead of shot. Hence it will occasion no surprise that the germs burst through the strong covering with difficulty, and that sometimes weeks elapse before the seedlings appear, one or two at a time. To facilitate germination some growers file the seed, others soak it until the skin becomes sufficiently soft to permit of the paring away of a small portion with a sharp knife. In either case caution must be exercised to avoid injuring the germ. A safer mode of attaining the object is to soak the seeds in water, placed in a greenhouse or stove, for about twenty-four hours before sowing. After soaking the seeds it is necessary to keep the soil constantly moist, or the germs will certainly suffer injury. The number of seeds sown should be recorded, so that it may be known when all are up. The first sowing should be made in January, in a temperature of about 75°, and as fast as the seedlings become ready transfer singly to small pots. As Cannas are gross feeders they must have a rich, porous compost, and an occasional dose of liquid manure will prove beneficial, especially when the pots are full of roots. If the seedlings from the January sowing are regularly potted on and properly managed they will begin to flower in June or July. Either the plants may be turned out into a rich soil, or the pots can be plunged, and after flowering in the open until late in autumn the plants can be lifted for another display of bloom in the greenhouse. In warm districts and in dry, sheltered situations, the roots may be left in the open ground all the winter under a covering of ashes; but they must be lifted from a damp, cold soil, and stored in a frame during the winter months. We have only mentioned January as the month for sowing, but seed may be put in up to midsummer, or even later, following the routine already indicated.
Dianthus Caryophyllus fl. pl. Hardy perennial
The Carnation belongs to the aristocracy of flowers and has attained the dignity of an exclusive exhibition. But in addition to their merits as show flowers, Carnations make conspicuous ornaments in the garden and the home, and it has been found that seed saved with skill from the finest varieties will produce plants yielding hundreds of flowers of which the grower need not feel ashamed. Since the introduction of the early-flowering class, which can easily be had in bloom within six months from date of sowing, an immense impetus has been given to the culture of Carnations from seed, and with judicious management it is not a difficult matter to insure a succession of these delightful subjects almost the year through. For the decoration of greenhouses and for providing cut flowers, seedling Carnations have a special value, which has only to be known to be universally appreciated. No trouble should be experienced with high-class seeds, which germinate freely and save much time and labour in comparison with the more tedious process of propagation; while an occasional new break may at times reward the raiser.
The proverb that what is worth doing is worth doing well is peculiarly exemplified in the cultivation of Carnations, the difference between the results of good and bad work being immense. We therefore advise the preparation of a compost consisting of about three parts of turfy loam, to one part each of cow-manure and sweet leaf-mould, with a small addition of fine grit. A compost that has been laid up for a year, according to the orthodox practice of florists, is very much to be desired; but it may be prepared off-hand if care be taken to have all the materials in a sweet, friable state, free from pastiness, and as far as possible free from vermin. By laying it in a heap, and turning two or three times, the vermin will be pretty well got rid of. Sow from April until August in 4-1/2 inch pots, which must be thoroughly drained. The seed must be very thinly covered, and sheets of glass should be laid over to check evaporation. Place the pots in a closed frame, or if the season be genial a sheltered border will suffice. Immediately the plants are large enough to handle, prick them off into seed-pans, or round the edge of 48-size pots. Place these in a cold pit or in the greenhouse. Give shade and water until the plants have formed six or eight leaves, and then choose a moist day for planting out.