his should be cut back every
spring.

NEILLIA.--Thin out every year after flowering is past, cutting back the
old wood to strong young shoots.

NEVIUSIA.--This requires the same pruning as Neillia.

NOTOSPARTIUM.--Requires no pruning.

NUTTALLIA.--The single species of this flowers in February, and is
improved by a good thinning out of the old wood when blooming is past.

OLEARIA.--Requires no pruning.

ONONIS.--_O. rotundifolia_ should be cut down every winter, as it
flowers on the young wood. The remaining species flower on the older
wood, and need not be touched.

OSMANTHUS.--These should not be pruned unless a particular shape is
desired, when the plants may be clipped with a pair of shears in spring.

OXYCOCCUS.--This is a small creeping genus allied to Vaccinium, and
requires no pruning.

OXYDENDRON.--Remove seed-pods.

PALIURUS.--This attains the dimensions of a small tree, and should be
kept trimmed up for that purpose.

PARROTIA.--Thin out in spring after the flowers are past.

PAULOWNIA.--Keep to a single stem to a height of about 8 feet, and then
allow it to branch. If used for sub-tropical bedding, it should be cut
down to the ground every winter.

PERAPHYLLUM.--The solitary hardy species of this should not be pruned or
disturbed in any way if it can be avoided.

PERIPLOCA.--A climbing genus which should be thinned out in winter, and
only shortened back if necessary.

PERNETTYA.--These should not be pruned at any time.

PHILADELPHUS.--These should be thinned after flowering, and the old wood
cut back to strong young shoots. This is especially important with _P.
microphyllus_, _P. coronarius_, and _P. Lemoinei_ and its varieties.

PHILLYRAEA DECORA (_Vilmoriniana_).--This well-known shrub needs no
pruning.

PHOTINIA.--Requires no pruning.

PIERIS.--Remove seed-pods.

POTENTILLA.--Thin out after flowering, and shorten any old wood back to
strong young breaks.

PRUNUS.--When young, all the members of this genus that are grafted or
budded are improved by being cut back each spring until they have
attained a fair size and shape. More especially is this the case with
the Almonds, double-flowered Peaches, and the various flowering
Cherries. When older, they need only be thinned and the flowering Plums
and Cherries kept spurred in, but not too hard. _Prunus japonica_, _P.
nana_, and _P. triloba_ should be cut down to strong young breaks after
flowering, the resulting wood bearing better f