Pruning is the removal of plant parts to improve tree and shrub health, structure, and safety. Pruning is one of the most valuable procedures an arborist can perform; likewise, it can be harmful to a plant if done incorrectly or in an untimely manner. Proper pruning of trees and shrubs can enhance plant function and performance in the landscape as well as increase structural strength and lessen risk of failure. Pruning trees and shrubs at an early age helps
ensure structural strength and vigor at maturity. Mature plants, seemingly overgrown, also benefit from pruning to reduce or restore proper size and density instead of removal and replacement. Regardless of the situation, trees and shrubs stand to benefit from the proper planning of pruning activities.

Objectives of Pruning

  • Improve plant shape and appearance
  • Provide clearance for or reduce inference with structures, vehicles, pedestrians or other plants
  • Maintain plant health and vigor
  • Restore a plant damaged by storms, disease, or equipment
  • Reduce risk of plant or plant part failure
  • Improve or alter a view
  • Influence flower and fruit production

Methods of Pruning

  • Crown cleaning – removal of dead, diseased and/or broken tree or shrub parts.
  • Crown thinning – selective removal of live plant parts decreasing density in the canopy to increase sunlight
  • penetration or air movement within the crown and to adjacent lawns and landscape plants.
  • Reduction pruning – removal or shortening of live plant parts to reduce the overall size of a tree or shrub,
  • increase sunlight penetration or minimize inference with adjacent structures or other plants.
  • Structural pruning – removal of live plant parts to improve branching orientation, spacing, or growth rate.
  • Crown raising – removal of live or dead plant parts, generally in the lower part of a tree, to improve a view or improve overhead clearance for buildings, vehicles, equipment or pedestrians.
  • Restoration pruning – removal of live or dead plant parts to restore a tree or shrub to its natural growth habit or vigor or to minimize health and structural integrity issues caused by storm damage.

Qualifications for Pruning Trees and Shrubs

Pruning of trees and shrubs is an essential element of plant maintenance. An arborist must understand particular dynamics of pruning such as when to prune, how much live wood to remove, where to make the cuts and what tools to use. Knowledge of branch attachment physiology, plant biology and the short and long term effects of pruning are additionally essential for successful pruning. An ISA Certified Arborist is extensively trained in the technical
elements of pruning and held to a continuing education requirement. All pruning work performed by an arborist shall be completed in compliance with the ANSI A300 technical standard and the Z133.1 safety standard.