TREE
TOPPING or HOW TO CREATE A DISASTER Paul
Hetzler, Community Forestry Program
Cooperative Extension of St. Lawrence
County, NY Tree
topping is one subject I can really get worked up about. Topping is unprofessional,
unsightly, outrageous, immoral, unethical, and possibly contributes to rainy weekends,
bad breath, parking tickets, baldness and tooth decay. It is unthinkable, unbelievable,
wrong, horrible, awful, bad, yucko, blecch! Any questions? Oh, exactly what is
topping? Just a minute. Mmph- there, that’s better. Had to wipe the foam
off my mouth.
 OK,
tree topping is the cutting back of large portions of a tree’s canopy to
stubs or inappropriately small branches. Variably known as heading, dehorning,
hat racking and tipping, it has not been an accepted practice for at least 25
years. It is the most harmful practice visited on living trees by human beings.
(All right, besides cutting the whole thing down). Topping is believed to have
started as a method of clearing utility lines. This practice was perceived by
some as an appropriate way to reduce a tree’s height. (Possibly this was
encouraged by line clearing employees who went on to become "tree experts"
willing to do topping.) Thus topping jumped from industrial clearing to residential
"care".
Topping
shortens a tree temporarily, but does not alter those pesky DNA strands which
just insist the tree grow to its normal height. So, the tree re- grows as
programmed, but for various reasons the new top or branch that develops is much
weaker, and is more weakly attached to the parent wood than the original part
was. Then the tree that’s left standing (the "remnant tree") begins
to decay from the topping cut down. A column of decay develops in the center of
the tree which will eventually become as wide as the cut was. Imagine slicing
a building in half, destabilizing the bottom part, then rebuilding the top with
vastly inferior materials. Recipe for disaster? You bet! As the cheap imitation
(re- grown) parts get bigger, the point at which they are attached becomes increasingly
decayed. It may take as many as forty or fifty years, or as few as five or ten,
but as the bumper sticker says, "failure happens". Once the disastrous
long term effects (including long term liability) of topping became widely known,
it was abandoned by tree care professionals.
Not
only does topping create weak new growth, it also severely weakens the remnant
tree. The tree has to take "money out of the bank" (starch out of
storage) to re-grow at a time when much of its stored starches have been lost
by topping. Trees normally spend their energy reserves on things like making defensive
chemicals to protect themselves from diseases and pests. When they are too energy
deficient to do this, the result is a tree which is more vulnerable to decay,
disease, and insects.
The
difference between looking at a naturally formed tree and a topped tree is like
the difference between looking at classic architecture and a pile of construction
rubble. Trees generally add to property value, up to about twenty percent.
But a tree that is disfigured from topping can actually decrease property value,
and possibly the value of neighboring properties as well.
If
a short tree is desired, a short species must be planted. However, there is
an acceptable practice called crown reduction pruning which can reduce the height
of most trees in a way that does not harm them. Crown reduction takes a lot more
skill than topping, and can reduce a tree’s height by a maximum of about
twenty five percent. Of course, the tree will eventually grow back to original
height, but it will not be the hulking wretch that topping would produce. Crown
reduction works best on deciduous trees.
To
address concerns about a tall tree blowing over, there is a practice which can
lessen that risk. Crown thinning is the selective pruning of branches throughout
the canopy to reduce wind resistance. Again, this takes more skill and judgment
than topping. A tree company that tops trees probably lacks the expertise to perform
the correct procedures, and should be avoided. In fact, the International Society
of Arboriculture (ISA), a research and education association of tree care professionals,
advises the public that a tree company which advertises topping should NOT be
hired, for any work, period.
Tree
topping is probably the best way to turn a normally docile, peace- loving tree
into a snarling killer, or at the very least a snarling unsightly nuisance and
potential legal liability. |
