With the American
National Standard for pruning, ANSI A300, specifications can be
written in a virtual infinite number of combinations. The
following information is designed to help you understand exactly
what will be accomplished in a pruning operation.
Branch Size
A minimum or
maximum diameter size of branches to be removed should be
specified in all pruning operations. This establishes how much
pruning is to be done.
Pruning Objectives
Pruning objectives
should be established prior to beginning any pruning operation.
A300 provides two basic objectives.
Hazard Reduction
Pruning
Hazard reduction
pruning (HAP) is recommended when the primary objective is to
reduce the danger to a specific target caused by visibly defined
hazards in a tree. For example, HAP may be the primary objective
if a tree had many dead limbs over a park bench.
Maintenance
Pruning
Maintenance
pruning (MP) is recommended when the primary objective is to
maintain or improve tree health and structure, and includes hazard
reduction prunin,g. An example here might be to perform a MP
operation on a front yard tree.
Pruning Types
Hazard reduction
pruning and maintenance pruning should consist of one or more of
the pruning types noted below.
_____Crown Cleaning...
Crown
cleaning shall consist of the selective removal of one
or more of the following items: dead, dying, or diseased
branches, weak branches and watersprouts.
_____Crown Thinning ...Crown thinning shall
consist of the selective removal of branches to increase light
penetration, air movement, and reduce weight.
_____Crown Raising... Crown raising shall consist of the
removal of the lower branches of a tree to provide clearance.
_____Crown Reduction, or Crown
Shaping… Crown Reduction decreases the height and/or
spread of a tree. Consideration should be given to the ability of
a species to sustain this type of pruning.
_____Vista Pruning… Vista Pruning is selective thinning of framework limbs or specific areas of the
crown to allow a view of an object from a predetermined point.
_____Crown
Restoration... Crown Restoration pruning should improve
the structure, form and appearance of trees which have been
severely headed, vandalized, or storm damaged.
The
three links below have helpful information on tree
pruning
