Pruning

Tree pruning can be a useful tool in insuring the health and structure of your trees. By proactively maintaining a tree’s canopy, many conflicts between trees and properties can be avoided before they become a larger issue. In most cases a pruning plan is discussed with the client to address the goals of the work. Common goals include:

  • Physical clearance from buildings or over sidewalks, roads or driveway

  • Additional sunlight to roofs, solar panels, gardens, lawns or other plantings

  • Removing dead, dying, diseased, weak or structurally compromised limbs (crown cleaning or dead wooding)

  • Thinning or canopy lifting to increase air flow through or underneath canopies

  • Crown reduction - reducing the height and or width of the canopy

  • Retrenchment - the removal of dead or declining branches in older trees in an effort to stimulate growth in a more compact canopy

 

Proper pruning follows several critical rules in order to best preserve the health of the tree:

  • Pruning is best started early as it allows for the best chance of creating a strong growing structure that fits the client’s goals without doing damage to the tree.

  • By pruning a tree when it is young, poor branch attachments with included bark can be removed early, leaving only strong healthy branch unions. Trees in the Prunus genus (Cherry) are prone to this weakness. In Anchorage, we have the mayday and amur cherry that frequently have large limb failure.

  • Spurs are not used when accessing a tree’s canopy. By not using spurs, we are not creating wounds through which disease can enter. Whomever you hire, ensure that they can access the canopy without spikes.

  • No more than 25%-30% of the canopy will be removed in any growing season. If a client’s goals can not be achieved under this limitation, pruning will be completed over successive seasons.

  • Proper pruning cuts are imperative. By making proper cuts we ensure that we maintain a strong growing structure and allow the tree the best chance of healing over, or compartmentalizing, the exposed heartwood.

  • We don’t top trees. Topping trees makes a wound that cannot be compartmentalized(healed) by the tree. This leads to the ingress of water and fungus which leads to rot and structural damage. Topping also instigates epicormic growth, one of the ways trees deal with stressors or traumas, which is seen as a frenzied growth of many poorly attached leads(branches.) Being poorly attached means that over time, we can expect to see failures where they break off and fall down.

  • What we can do is reduce canopies by cutting back to a suitable branch, one that is at least 1/3 the diameter of the original.

 

For more information about pruning and industry standards, visit this site - ISA proper pruning practices