nd _B. paniculata_ only
requires thinning out if it becomes too thick, which is not a very
common occurrence.

CALLUNA (the Ling).--This and its numerous varieties should have the old
flowers cut off as soon as they are past, and any long or straggling
growth cut back at the same time.

CALOPHACA.--The solitary representative of this genus is rather inclined
to become straggly if growing at all freely. When this is the case, the
plant is benefited by the cutting back of the longer shoots in winter.

CALYCANTHUS.--These require an occasional thinning of the branches, and
any long shoots may be shortened with advantage.

CAMELLIA.--These, which should be grown outdoors much more than they
are, should be cut down if they get unhealthy or unshapely, which should
be done in April. Otherwise no pruning is required.

CARAGANA.--Cut away all the straggling or misplaced branches.

CARMICHAELIA.--Requires no pruning.

CASSANDRA.--See CALLUNA.

CASSINIA.--These are grown more for their foliage than for their
flowers, and should be cut down in the winter or early spring. This can
be done annually or biennially according to whether the plants are
growing strongly or not.

CASSIOPE.--See CALLUNA.

CATALPA.--This genus contains some of our handsomest flowering trees,
all of which require careful pruning after the flowers are past,
thinning out the weakly wood, and shortening any long branches.

CEANOTHUS.--Of these, _C. americanus_, _C. azureus_, _C. integerrimus_,
and the garden hybrids, such as "Gloire de Versailles," "Marie Simon,"
"Ceres," &c., flower on the young wood, and should be cut back in
spring, allowing only sufficient shoots to remain to form a
well-balanced plant, and shortening them back to within two or three
eyes of the old wood. The remaining species flower on the old wood, and
merely require a shortening back of the stronger shoots and a thinning
out of the weakly ones after the flowers are past.

CELASTRUS.--A climbing genus of strong and vigorous habit with showy
fruits. They only require sufficient pruning in winter to keep them
within bounds.

CERCIS.--Requires no pruning, except such as may be necessary to make
well-shaped plants, which should be done after flowering.

CHIMONANTHUS.--The shoots of this should be shortened back after
flowering, and if on a wall they should be spurred in.

CHIONANTHUS.--See CERCIS.

CHOISYA TERNATA.--This only needs thinning after the flowers are over
and ol