Cyanus(_Cornflower_).--Very pretty and free-blooming hardy annuals. Sow the seed in the open in autumn for an early display of flowers, or in March for a later one. Thin out to 2 ft. apart. Bloom in July. Height, 2 ft. to 3 ft.
Cyclamen.--Charming winter and spring blooming bulbous greenhouse plants, which thrive in a mixture of sandy loam and vegetable mould. They require a moist atmosphere and a uniform temperature not lower than 50 degrees. They may be increased by seed sown in slight heat as soon as it is ripe. Plant the bulbs in October, also in February and March, placing them so that the crown is level with the top of the pots. One full-sized bulb is sufficient for a 6-in. pot, which must be provided with good drainage and placed on a layer of coal ashes that is kept constantly moist. Water moderately till growth begins, then increase the supply. Give a little liquid manure, in a weak state, if a large quantity of flower-buds appear. When the blooming season is over, plunge the pots in a shady, well-drained border, and when the leaves start afresh turn the plants carefully out of the pots, so as not to injure their roots, and re-pot in fresh soil. C. Persicum flowers in February, and C. Neapolitanum in April. C. Europeum is a hard variety, thriving in any situation. It produces sweetly-scented flowers throughout July and August. It does best when planted under trees, or in partial shade on rock-work, in well-drained, good loamy or peaty soil mixed with a fair proportion of brick rubble. Plant the corms in September 3 in. apart, and 1-1/2 in. deep. Height, 6 in. to 9 in.
Cydonia (_Pyrus_).--These hardy plants are well adapted for trellis-work, but are more effective when grown as bushes, and flower more freely than when trained to the wall, the bloom often lasting to the winter. They will grow in any soil, and are increased by suckers. Height, 4 ft. and upwards.
Cyperius Alternifolius.--A stove grass which will grow in any soil, but requires a plentiful supply of water. It is increased by dividing the roots. Height, 2 ft.
Cypress (_Cupressus_).--Among these useful conifers C. Lawsoniana has no superior as a single specimen for the decoration of the lawn. Of free growth and perfectly hardy, it succeeds in almost any soil or situation. C. Fraserii is also hardy, of erect habit, and of a rich glaucous hue. When it attains a good size it is very ornamental. The beautiful silver variegated variety Argenteo Variegata deserves a place in every shrubbery. Nana Alba Maculata is a dwarf globular plant, the slender branches of which are tipped with white, giving it the appearance of being partly covered with snow. Pygmea is a compact dwarf-growing variety suitable for the centre of small beds and for rock-work. Japan Cypresses are elegant little shrubs, one of the finest being Retinospora Ericoides, whose peculiar violet-red leaves contrast charmingly with light green plants. Any of the above may be increased by cuttings. They succeed best in a rich, deep loam, and are improved by thinning out the branches where too thick, and pinching out the stronger shoots where too thin, so as to encourage new growth.