Horticulture Principles and Practices

Bud withers as
cut end dries back
during healing
FIGURE 19–5 Distance of cut
from the nearest bud is critical to
the survival of the bud. If a cut is
too close to the bud, it might
wither with the advance of drying
tissue as part of the healing
process.
Cut too close to bud
Bud unaffected
by drying during
healing of cut
Cut proper distance
from bud
a b a
a
b
a
Bud "b" removed;
bud "a" grows inward
into plant canopy
b
Pruning above bud "b"
causes new branch to
grow outward to open up
plant canopy
FIGURE 19–6 The direction of
new growth after pruning depends
on the potential direction of growth
of the bud closest to the cut. If an
outward-pointing bud is the last
bud, the shoot will grow outward.
An inward-pointing bud should be
targeted with care since it defeats
the purpose of pruning in certain
cases by encouraging new growth
to crowd the inner part of the
tree canopy.
Direction of
potential bud
growth
7. The ideal cutting position is close to a bud at a fork or branch or just above the
collar of a branch.
8. When cutting with shears or pruners, the thin blade should be nearest the bud or the
trunk, which permits the desired cut.
19.5.3 CARING FOR WOUNDS
Plants have natural defense mechanisms that are triggered upon injury. First, a layer of
waterproof material called suberin is produced to protect the exposed tissues of the
wound from drying. Next, callus growth occurs to produce new tissue to close up or heal
the wound. It is important that wound closure occur without delay to avoid invasion by
decay organisms. The rate of healing depends on a number of factors:
Suberin
A hydrophobic material
that occurs on the inner
surface of a cell wall.
1. Size of wound. A large wound heals slowly.
2. Location of wound. Generally, wounds occurring at lower levels on the plant heal
more quickly than those at higher levels.
19.5 Pruning Techniques 575