Right Tree / Right Place
Mulching & Staking
Tree Root Myths
Pine Bark Beetles
List of Figures
List of Video Vignettes
[ Tree Dissection ] [ Utility Lines ]
Topping Hurts- General Information:
Iles (1989, p.51) described topping as “the drastic removal of large branches with
little regard for location of the pruning cuts”. Although topping trees is
a common practice in many communities, it is NOT a professional method for
pruning trees. It is not a practice that should be performed by any
certified arborist because there are professional pruning techniques to limit
the height of a tree.
Proper Height Reduction of a Mature Tree.
Topping practices do not
follow the rules of pruning that protect the branch collars or that stipulate
size limits for pruning to lateral branches, thus they are not made in a
professional manner and leave stubs of branches in the canopy. These stubs are
not protected from decay organisms, and open the tree to invasion by insects and
decay. This decay can penetrate to the lower branches and trunk of the tree and
cause its rapid decline and possibly death. These problems are shown in Figure
or “rounding over” is mistakenly believed to control the height of a tree.
However, the new stems will soon grow to be the same height as the tree is
genetically programmed to be. But the new stems will be numerous and crowded and
weakly attached at the point of topping. Many of these will die back and fall
off during windy weather.
8-3) Tree Topping Example.
tree topping events are visible in this picture. The limbs grew from stubs of
three branches, and the new limbs are crowded.
lower left branch shows the weakened precarious attachment of the new limb. The
large fresh wound shows the size of the stub branch.
lower right branch shows the cavity that developed in the original stub,
weakening the entire tree.
of Improper Tree Topping: Limb
Dissection Example - Video
Vignette (See it live!)
Eight Good Reasons (NADF,
1989) to NOT "Top" :
removes so much of the crown that it upsets the crown-to-root ratio and
limits the food-making ability of the tree.|
|Shock: the canopy
of leaves casts shade on the internal branches. Topping removes the shade
and exposes the internal bark to sun scald.|
|Pests and Disease: topped branches have large wounds that cannot seal nor defend the wound from
insects and decay.|
|Weak Limbs: new
sprouts develop at the edges of the cut branches, and are weakly attached.
If the stub rots, the sprouts will break even sooner.|
|Rapid New Growth:
height control by topping is doomed to fail. The new branches grow fast and
furiously to the original height, but much more crowded.|
|Tree Death: some
species, e.g. beech, do not tolerate topping and the reduced foliage
may cause the tree to die.|
trees are so disfigured that they will never recover their original grace.|
topping can be done quickly because good decisions about pruning are not
needed. But trees that die will need replacement, the ugly trees reduce
property values, the dead stubs become liabilities, and more maintenance
will be needed.|
There is a pruning technique
that looks like topping, called pollarding (Harris,
1999). It works only
on certain trees, and it requires frequent and consistent pruning. Pollarding
consists of cutting back branches to a selected point of fixed height, but
continuing to cut the branches every year or every other year to
create a compact canopy.
differences between topping and pollarding.
Common, but inappropriate;
Stem diameter and age not
Practiced on any trees of
Return pruning may not
Causes decay in cut
Creates weak attachments
that may become dangerous;
Can decrease the tree life
Rare, but appropriate
Begins when tree is young;
Applied every one or two or
All shoots are removed each
Shoots are only 1-inch
diameter when removed;
Does not cause trunk decay;
Creates good structure;
Can have extended life