Agriculture Reference
In-Depth Information
Shrubs that flower once a year
Many shrubs flower on the new growth
resulting from last year's growth (see
Table 4.3)
Whatever the case, the standard rule of
thumb is to prune directly after flowering to an
outward-facing bud.
Shrubs that also carry
ornamental berries/hips are treated
differently (see below). Once your shrub has
become established, shortening back
vigorous shoots and pruning out spent
flowers has the advantage of saving the plant
the energy needed to form seed, a
metabolically expensive exercise for the
plant. The energy saved can then be directed
into providing new growth to carry next
year's flowers.
Table 4.3
Shrubs to prune after or during flowering
Ballota
Buddleja
spp. Butterfly bush
Callistemon
Bottlebrush
Choisya
Mexican orange blossom
Cistus
spp.
Correa
Native fuschia
Crowea
Deuztia
Erica
Heath
Eriostemon
spp.
Erysimum
spp.
Forsythia
Garryaeliptica
Tassel bush
Genista
Broom
Grevillea
Spider flower
Hebe
Kolkwitzia
Beauty bush
Lavandulaangustifolia
English lavender
Lavatera
Leonotis
Leptospermum
Lupinusarboreus
Perovskiaatriplicifolia
Russian sage
Philadelphus
Mock orange
Plectranthus
Plumbagoauriculata
Rosmarinus
Rosemary
Sambucus
Elderberry
Streptosolenjamesonii
Syringa
Lilac
Tamarix
Thymus
spp. Thyme
Viburnumxburkwoodii
Viburnumopulus
Snowball tree
Weigeliaflorida
It is important to prune shrubs that f flower
early in the season straight after they have
f flowered before the new growth has fully
developed. Pruning after this time not only
means that you put up with dead f flowers,
but also that the long lanky growth will
produce few side shoots to carry next year's
f flowers. By removing the end of the
branch (removing the apical/terminal bud)
new growth is forced sideways making
your shrub bushier and more f floriferous
next year (see pages 3-4, 'Apical' and
'Axillary buds', and Figures 1.4 and 1.5). The
viburnum
in Figure 4.8 illustrates the
general principle.
Always cut behind the f flowers no matter how
tempting the new growth may be. If you
don't, the result will be a very straggly affair
with few f flowers. Plants that put on new
vegetative growth almost as soon as the
f flower opens are the hardest for the new
pruner to remove.
Callistemon, Rhododendron
and
Daphne
species
are examples. Harden
your heart and cut to behind the f flower or
you will be left with a straggly mess. Another
advantage of pruning at or after f flowering is
that you can cut stems to enjoy indoors, with
the added joy that you are helping your
plant reach its full f flowering potential (see
Figure 4.9).
