Clitoria.--A greenhouse climbing or trailing plant, which thrives in a
mixture of loam, peat, and sand. Cuttings will strike in heat, but it
is more readily grown from seed.
Clivias (Caffre Lilies).--Most beautiful evergreen plants for
the greenhouse. The soil most suitable for them is a compost of
leaf-mould, loam, and sand. Give a liberal supply of water when in
full growth, but from September to February keep them only moderately
moist. Shade from strong sunshine, and keep the temperature at from 60
to 70 degrees. They will not bear much disturbance. Seed may be sown
in bottom-heat early in spring, or they may be increased by suckers.
Cobaea Scandens.--This rapid climber is well adapted for the
conservatory, but it will thrive in the open air if the root is
protected during the winter. If planted against a rough wall its
tendrils will catch in the crevices and support it without any
assistance. It requires plenty of room and a rather poor soil,
otherwise it runs to leaf instead of to bloom. The tops of the shoots
should be constantly pinched off, to induce thickness of growth.
Cuttings of firm side-shoots taken in summer will root under glass in
a little moist heat; but it is best raised from seed, sown sideways,
in a hotbed in March. Its blue and purple flowers are produced in
August. Height, 10 ft. to 20 ft.
Cob Nuts.--See "Filberts."
Cockscomb.--These tender annuals should be sown on a moderate hotbed
in March or April, in pans of leaf-mould and sand, covering with 1/4
in. of soil. When a couple of inches high place them in small pots,
replace them on the hotbed, and give shade till they have taken fresh
root. When the weather is favourable let them have a moderate amount
of fresh air. Afterwards shift them into larger pots, and when the
combs are full grown place them in the greenhouse, taking care not to
allow any damp to lodge on them, at the same time supplying them
well with water and all the air possible. Height, 9 in. (See also
"Celosia.")
Codonopsis.--These hardy perennials are best grown in sandy peat and
loam. They are easily raised from seed or cuttings, and produce their
flowers in July and August. Height, 1 ft.
Coix Lachryma (Job's Tears).--A half-hardy, annual, ornamental grass
bearing clusters of beautiful pearl-like seeds. Sow in a warm spot in
April, barely covering the seed with fine soil, and keep the surface
of the ground moist till germination is ensured. Height, 1-1/2 ft.
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