GARDENING
Advice on
Pruning
W
hen trees cause problems,
pruning is often seen as a
suitable alternative to felling
- but pruning without thought for the
consequences can actually create further
problems.
Tree growth is regulated by hormones,
and pruning disrupts the hormone
distribution and subsequent growth.
Without careful thought, this can result
in a major change of growth habit until
the systems can be restored. Reducing
the canopy also reduces the ability to
produce the energy necessary for health
and growth.
The first questions to ask before cutting
are: what is the problem and what is the
desired outcome? If a tree is weakened,
then reduction pruning to ‘reef the sails’
would reduce the wind-loading and
might be sufficient to reduce the level of
risk the tree poses without resorting to
felling. Other reasons may be to reduce
shade or prevent branches coming into
contact with buildings or wires. Once the
problem is identified, the consequences
of the pruning need to be considered
against the desired outcome, and then
the correct treatment applied.
There are many fallacies and
“The first questions
to ask before
cutting are: what
is the problem and
what is the desired
outcome?”
70
misunderstandings around tree pruning.
Reducing weight is rarely necessary
when a tree is weakened; the critical force
typically comes from the ‘sail area’ and
the leverage. Reducing the canopy in an
attempt to reduce the number of leaves or
seeds is actually unlikely to achieve much,
as the response of the tree will be to
rapidly replace the lost canopy and if the
stress is too great it can trigger a response
that puts all remaining energy into seed
production, ensuring the next generation.
Pruning to ‘reinvigorate’ does nothing
but weaken, as the vigorous response
seen is nothing but stress; all available
energy is being put into repairing the
canopy that has been removed, using
surplus energy that would otherwise
be available for root development and
defending the tree against pests or
diseases. Pruning to control root growth
is another fallacy; pruning can starve roots
and they will die but not in a predictable
or controlled way. Another common
misconception is that trees ‘need’ pruning;
however, they have developed and lived
happily for quite a few years.
Trees do not need pruning until
they come into conflict with human
activities and desires. An arboriculturist
can help make an informed decision
when it comes to managing trees
using knowledge, understanding and
experience. Ensuring the arborist who
carries out the work is competent and
experienced but who also understands
what’s required, is the final link in
the chain of good arboricultural
management.
For more information call Ben Riches
of Arb Advice on 07544 079296, or visit
www.arbadvice.co.uk.
www.visitilife.com
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