d wood removed.

CISTUS.--Those which are hardy of this genus should be cut back each
spring while in a young state, but when they have attained a flowering
size no pruning is required. The cutting back of young plants induces a
bushy habit, and also keeps them from weakening themselves by blooming
and seeding.

CLEMATIS.--The garden forms of this genus are divided into two sections,
of which _C. Jackmani_, _C. lanuginosa_, _C. Viticella_, and _C.
aromatica (C. caerulea odorata)_ are the types of those which flower on
the young wood, and which require cutting back close to the old wood in
the winter; while _C. florida_, _C. patens_, and _C. montana_ are the
types of those which flower on the ripened wood of the previous year,
and merely require a thinning out of weakly or unnecessary growth. Of
species other than those mentioned above, _C. Flammula_, _C.
paniculata_, and _C. Vitalba_ flower on the young wood; and the
remaining species are either herbaceous or flower on the old wood.

CLERODENDRON TRICHOTOMUM.--Thin in spring.

CLETHRA.--These practically require no pruning, but long shoots may be
shortened and weakly ones cut away with advantage.

COLUTEA.--These make better plants and flower later if they are cut back
every winter. _C. istria_ (a rare species) should not be cut down if
flowers are desired.

CORNUS.--The strong-growing shrubby Cornus, such as _C. alba_, _C.
Amomum_, _C. Baileyi_, _C. pubescens_, and _C. stolonifera_ require an
annual thinning out, and those with brightly-coloured stems should be
cut down every spring for their effect during the following winter. The
remaining Cornus require little or no pruning.

COTONEASTER.--The large-growing species should be pruned in late summer,
but only sufficiently to keep them within bounds; _C. Simonsii_ requires
cutting down annually while young to make it bushy, and the
dwarf-growing kinds are best left alone.

CRATAEGUS.--Keep the heads well thinned out to allow light and air to
the centre of the tree. This should be done in late summer.

CYTISUS.--These require very little pruning, with the exception of _C.
nigricans_ and _C. capitatus_, which flower on the young wood, and
should be cut back annually. The other species and varieties make better
plants if they are cut down each year while in a small state, but they
should be left alone when they have attained flowering size.

DABOECIA (the Irish Heath).--Cut away all old flower stems in early
wi