lowers than the old wood.
If any of these three latter are grown on a wall they should be spurred
back hard after blooming.

PTELEA.--When young, trim these to form small trees, and do not allow
them to develop into ungainly bushes. When older, they require an
occasional thinning. _P. trifoliata var. aurea_, a golden form which is
not grown so much as it deserves to be, should be cut back annually or
biennially, the young wood being better coloured and bearing larger
leaves than the old.

PYRUS.--The wild Pears should be spurred in the same manner as adopted
for fruiting Pears, though not quite so hard. The wild Crab-apples, such
as _P. baccata_, _P. floribunda_, _P. spectabilis_, &c., should be cut
back every spring until they have formed well-balanced heads. Afterwards
an annual thinning and a shortening of the longest shoots after
flowering is sufficient. The remaining sections of Pyrus merely require
an occasional thinning. _P. japonica_ should be kept spurred in, whether
growing on a wall or in the open, and in the latter case should not be
allowed to become a mass of weakly shoots.

RHAMNUS.--These should be thinned out if becoming too thick, but, as a
rule, they require very little pruning.

RHODODENDRON (including AZALEA).--Remove all seed-pods immediately the
flowers are over, and any plants that are in a sickly condition should
be cut down at the same time. By doing this a season or two of flower is
lost, but it is practically the only means of bringing a weakly plant
back to health again.

RHODOTYPUS.--Cut away old wood, and encourage the strongest of the young
growths.

RHUS.--Keep these well thinned out, and destroy all suckers that appear,
unless wanted for stocks. Gloves should always be worn when handling any
of the Rhus, as the sap of _all_ is poisonous to a certain extent. _R.
Toxicodendron_ is _very poisonous_. This should never be forgotten. If
used for sub-tropical gardens cut down to within two eyes of the base.
Select the strongest eye and rub the other off. Always use gloves in
handling this shrub. It should never be planted where children have
access to it.

RIBES.--All the Ribes are improved by being cut down annually while in a
young state, but when older, a yearly thinning out of the old wood is
sufficient.

ROBINIA.--This is a genus that requires very little pruning when the
members of it have attained a fair size, an occasional thinning being
all that is necessary. In a young sta