ANSI A300

With the American National Standard for pruning, ANSI A300, specifications can be written in avirtual infinite number of combinations The following information is designed to help youunderstand exactly what will be accomplished in a pruning operation.Branch Size — A minimum or maximum diameter size of branches to be removed should bespecified in all pruning operations. This established how much pruning it to be done.

Pruning Objectives

Hazard Reduction Pruning (HRP) — Is recommended when the primary objective is to reduce thedanger to a specific target caused by visibly defined hazards in a tree. For example, HRP may bethe primary objective if a tree has many dead limbs over a park bench.

Maintenance Pruning (MP) — Is recommended when the primary objective is to maintain orimprove tree health and structure, and includes hazard reduction pruning. An example here mightbe to perform an MP operation on a front yard tree.

Pruning Types

Hazard reduction pruning and maintenance pruning should consist of one or more of the pruningtypes noted below:

Crown cleaning — The selective removal of one or more of the following items: dead, dying ordiseased branches, weak branches and watersprouts

Crown thinning — The selective removal of branches to increase light penetration, airmovement and to reduce weight

Crown raising — The removal of the lower branches to provide clearance

Crown reduction or shaping — Decrease the height and/or spread of a tree. Considerationshould be given to the ability of the species to sustain this type of pruning

Vista pruning — The selective thinning of framework limbs or specific areas of the crown toallow a view of an object from predetermined spot

Crown restoration — Should improve the structure, form and appearance of trees which havebeen severely headed, vandalized or storm damaged.