Part 12

Colchicum (Autumn-Flowering Crocus).--Plant the bulbs in February in light, loamy soil, placing them 2 in. deep and 3 in. apart. They are readily increased by off-sets from the bulb. September is their flowering season. Height, 3 in. (See also "Bulbocodium.")

Coleus.--Tender perennial shrubs of some merit, requiring the protection of a greenhouse. Keep the plants root-bound and near the glass, with a good supply of heat and moisture. They succeed best in a mixture of loam and peat. Cuttings of shoots 3 in. long planted in sand, covered with a glass, and plunged in heat 60 to 70 degrees, will strike. Pot off singly in loam and sand. Bloom in June or July. Height, 2 ft. to 3 ft.

Colletia.--Ornamental evergreen shrubs. A mixture of peat and loam, with a sheltered position, is their delight. Cuttings will strike in sand if covered with glass. They produce their flowers in July. Height, 2 ft. to 3 ft.

Collinsia.--Most elegant hardy annuals, doing well in any garden soil. The seed is sown in autumn for early flowering, and in spring for a later display. Bloom May to August. Height, 1 ft.

Collomia.--Hardy annuals, possessing little beauty. Treat as Collinsia. Flower in July. Height, 1 ft. to 2 ft.

Colt's-foot.--This hardy perennial flowers before the leaves appear. It grows best in a moist, clayey soil, and may be increased by pieces of the running root.

Columbine.--See "Aquilegia."

Colutea Arborescens (Bladder Senna).--A shrub with Acacia-like leaves and producing yellow Pea-shaped flowers in July, followed with bladder-shaped seed vessels. It will grow in any soil, and may be raised either from seed or cuttings taken in autumn. Height, 10 ft.

Commelina Sellowina (Blue Spider Wort, or Day Flower).--A pretty greenhouse climber, bearing cobalt-blue flowers. It should occupy a sunny position, and be watered freely from March to September, after which very little should be given.

Commelina Tuberosa.--Perfectly hardy plants, bearing in June blue or white flowers the size of a shilling. The bulbs may be planted in spring in any garden soil; the plants are increased by off-sets. Height, 1-1/2 ft.

Compost Heap.--Get a heap of dead leaves and press and jam them down as closely as possible. Then take as much manure, in appearance, as you have dead leaves, and for each cartload have two bushels of unslaked quicklime and some earth. Now spread upon the ground, in some out-of-the-way corner, a layer of the dead leaves, upon which sprinkle a layer of lime, and over that a thin layer of earth. Next lay on a covering of manure, then a layer of leaves, and one of lime and earth as before, and proceed in this way till all the materials are used up. It will be well, however, to give the heap a good watering whenever you come to the layer of leaves. This slakes the lime and hastens the decomposition of the vegetable matter. After letting it stand for about six weeks, begin at the top of the heap and turn it completely over, so that what was at the bottom will be at the top. Repeat this operation from time to time at intervals of six or seven weeks, until it has become perfectly friable and will powder through a garden-fork like dust. It will then be ready for use. This compost is invigorating to flowers of all kinds, and is so ready for them to assimilate.

Comptonia Asplenifolia.--This ornamental deciduous shrub is quite hardy, but requires a light, sandy loam or peat soil and a shady situation. It is increased by layers. Blooms in April. Height, 4 ft.

Cone Flower.--See "Echinacea."

Conifers.--Conifers (so called because they bear cones in place of ordinary seed) are mostly of tall growth, yet among the class are many low--growing evergreens well adapted for the lawn or border. Indeed, any of the specimens may be utilised in this way, but of course must be removed from the shrubbery or border before they attain undue proportions. They are hardy, and, generally speaking, not particular as to soil or situation. Firs, Pines, Cedars, etc., come under this heading, and mention is made in other parts of this work of those most suitable for the amateur's requirements.

Convallaria Prolificans.--This is one of the most beautiful hardy perennials known. It has large, deep-green foliage, with erect and much-branched flower-stems. The flowers are white, internally flushed rose; are very fragrant, and are produced from May to September. The plant will grow in any ordinary soil, and may be increased by dividing the root. Height, 2-1/2 ft.

Convolvulus (Morning Glory).--Showy plants. The tender species are well adapted for the stove or conservatory, and are best grown in loam and peat: cuttings strike freely in sand under a glass. The half-hardy annual kinds should be sown on a gentle hotbed in February, and when large enough transferred to the open; or they may be sown in the open in April. Hardy kinds merely require sowing in the open, early in spring. The stove and greenhouse annuals and biennials require to be sown in heat, and treated as other stove and greenhouse annuals and biennials. Flowering season, May to July. Height, 6 in. to 15 ft.

Coral Plant.--See "Erythrina."

Corchorus.--See "Kerria."

Cordyline.--A stove evergreen shrub, which may be grown in any light, vegetable mould or in peat and loam, and is easily increased by suckers. It flowers in spring. Height, 3 ft.

Coreopsis.--Very pretty and long-flowering. They all like a light, rich, and sandy soil. Cuttings of the stove kinds root freely under glass. Hardy perennials may be divided at the roots. The annuals may be sown either in the autumn or in March; they bear transplanting. Longipes flowers in April; Grandiflora in August. Useful as cut flowers. Height, 1-1/2 ft. to 3 ft.

Cornel.--See "Cornus."

Cornflower.--See "Cyanus."

Corn Salad (Lamb's Lettuce).--Sow in drills--the plants to stand 6 in. apart--from March till August, in well-drained sandy loam. Autumn sowings will stand the winter and prove useful in early spring. It must be gathered young.

Cornus Canadensis (Canadian Cornel).--A pretty herbaceous plant, suitable for moist parts of rock-work. It is very hardy, likes a light soil, and produces flowers from June to August. The roots may be divided in autumn, or in the early part of spring. Height, 8 in.

Cornus Mas (Cornelian Cherry).--This hardy deciduous shrub does well in common soil if a fair amount of moisture be given. Its yellow flowers are produced on bare stems from February to April. It may be increased by seeds, cuttings, or layers, autumn being the time to propagate.

Coronilla.--The greenhouse shrubs should be grown in peat and loam. They are raised by seeds and by cuttings. Most of the hardy perennials need protection in winter, therefore they are best grown in pots. These are propagated by seed or division. The annuals need no special treatment.

Coronilla Iberica.--A pretty creeping hardy perennial suitable for rock-work, on which its bright yellow flowers are very attractive during June and July. It thrives best in a mixture of peat and loam, and may be increased by seeds or division of the roots. Height, 6 in.

Correa Cardinalis.--An evergreen greenhouse shrub. Place in equal parts of sand and loam, and propagate by cuttings, which should have plenty of room, as they are liable to damp off. July is its flowering season. Height, 4 ft. C. Magnifica is also a capital plant.