Cuckoo Flower.—See "Cardamine."
Cucumbers.—A rich, loamy soil is most suitable for their growth. Sow frame varieties in a heat of 75 degrees or 85 degrees during February and March for summer use, and when the plants are of sufficient size transplant to a well-prepared hotbed. Sow again in September for winter use. The hardy or ridge cucumbers (which are not suited for frame or hothouse culture) should be raised in a frame or hot-bed in April, and planted out about the middle of May in a warm border on strawed ridges prepared with good stable manure, placing a hand-glass over each plant until it is well established.
Cunila Mariana (Dittany).—This hardy perennial produces heads of pretty purple flowers from July to September. It is not particular as to soil, and can easily be increased by division. Height, 1 ft.
Cuphea.—Shrubs of a rather pretty description. The stove varieties require a sandy loam to grow in, and may be propagated by cuttings. The annuals should be sown on a gentle hotbed, and when strong enough potted off and kept in the greenhouse; they should not be moved into the open before the end of May. The perennial species if sown early make good bedding plants the first year; they need protection in the winter.
Currants.—Black.—A rich, deep soil and a moist situation, together with partial shade, are most suitable for their growth. They succeed better as bushes than as espaliers or trained to walls. Cuttings of the previous year's growth are taken in autumn and planted firmly 1 ft. by 6 in. apart. In two years shift every alternate plant so as to allow room for expansion, and plant out finally to a distance of 5 ft. In pruning the bushes, remember that the fruit is borne on the young wood, therefore only sufficient should be cut away to allow of the admission of air and sunshine and the further growth of young branches. A portion of the old wood should be removed each year. Mulch the roots, and keep the plants supplied with water in dry seasons. Baldwin's Black, Ogden's Black, Black Naples, Lee's Prolific, James' Prolific, and Old Black are among the best.
Red and White.—An open, sunny position is needed. The soil that suits them best is a deeply-manured, stiff loam. They are readily raised from cuttings—which should be as long and strong as possible—taken in autumn. Cut away all the eyes except the three uppermost ones, and plant firmly in rows 1 ft. by 6 in. apart. Transplant at the end of the second year to a distance of 5 ft. apart. While the plants are young cut out all the top centre branches, cutting always to an outgrowing bud, so as to give a cylindrical form to the bush. In further pruning leave the leading shoots untouched, but shorten all others to 4 in. or 6 in., and cut out all old, mossy wood. Towards the end of June is a good time for cutting the young wood away. The fruit is produced on spurs. In the autumn of each year carefully dig in a good dressing of half-rotted manure, in such a manner as not to injure the roots. Among the leading red varieties are the following:—Champagne, Cherry, Chiswick Red, Houghton Castle, Raby Castle, and Red Dutch. Of the white fruit the White Dutch and the Cut-leaved White are the leaders. In plantations they should stand from 4 ft. to 6 ft. apart.
Currants, Flowering.—See "Ribes."
Cyanthus Lobatus—A small, but very beautiful procumbent perennial, well adapted to fill moist places on rock-work if the situation is open and sunny. A mixture of vegetable mould and sand suits it, and it is best increased by cuttings placed in moist peat. It flowers in the autumn, the flower-stems being from 6 in. to 1 ft. in length.
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.