Calandrinia.--Very pretty hardy annuals. They grow well in sunny
places in a mixture of loam and peat, and may be raised from seed sown
in the spring or by cuttings placed under hand-glasses. Bloom in July.
Height, 6 in. to 1 ft.
Calceolaria.--Many of the varieties are suitable for the greenhouse
only. They may be grown from seed, but as this is so small it should
not be covered; and in watering them it is best to stand the seed-pans
in water so that the moisture ascends, as watering from the top might
wash the seed too deeply into the soil. July and August are the two
best months for sowing. The half-shrubby kinds make fine bedding
plants. They are easily reared from cuttings. These are best taken
in October. Put them in light, sandy mould on a well-drained north
border; press the earth round them, and cover with a hand-glass. In
very frosty weather a mat should be laid over the glass. Pot them off
in spring; give plenty of air, and plant them out at the beginning of
June, or before, if weather permits.
Calendula (Marigolds).--Very showy hardy annuals. They merely
require sowing in the open in autumn for an early display of bloom,
or in spring for a later show, but the autumn sowing gives the more
satisfaction. Flower during June and July. Height, 1 ft.
Californian Plants.--Great care should be taken not to allow the sun
to strike on the collar of any of the plants from California, as they
readily succumb if it does so.
Calla.--These showy plants, sometimes called Arum, are worth
cultivating. They make handsome pot-plants, bearing fine white flowers
in the spring. May be grown from seeds, or roots may be divided.
They are quickly increased by off-sets from the root in August or
September. Plant the off-sets from the fleshy roots singly in small,
well-drained pots of sandy loam with one-fourth leaf-mould or
well-rotted manure, and keep them in a very warm situation. Water them
well while in growth, scantily after the leaves begin to wither, and
afterwards give only enough moisture to keep them alive. Leave the
plants in the light while the leaves die off, and then place them in a
shed, in complete repose, for a month or so. Re-pot them in October
or November, and give plenty of water. They may stand in saucers of
water, but this must be changed daily. They flower from May to July.
Height, 2 ft.
Callichroa.--A hardy annual which well deserves a place in the garden
border, both on account of its dwarf and slender habit and also the
colour of its flowers. It is satisfied with any ordinary soil. The
seed is raised on a hotbed in March, or in the open in April, and it
blooms in the autumn. Height, 1 ft.
Calliopsis.--See "Coreopsis."
Callirhoe (Digitata).--Hardy annuals demanding but little attention.