Pruning Techniques

Tree Care

Pruning Techniques

Proper pruning of trees requires knowledge of plants, their structure, growth patterns and response to pruning. There are a number of pruning techniques that qualified ISA certified arborists practise to provide the best tree care. The approved techniques are; Cleaning, Thinning, Raising, and Reduction. Topping is not an approved technique.

Mumby’s Tree Services Ltd. adheres to the industry standard ISA code of ethics in all ways and specifically in regards to pruning.

Pruning Techniques
Specific types of pruning may be necessary to maintain a mature tree in a healthy, safe, and attractive condition.

Cleaning is the removal of dead, dying, diseased, crowded, weakly attached, and low-vigor branches from the crown of a tree.

Thinning is the selective removal of branches to increase light penetration and air movement through the crown. Thinning opens the foliage of a tree, reduces weight on heavy limbs, and helps retain the tree’s natural shape.

Raising removes the lower branches from a tree in order to provide clearance for buildings, vehicles, pedestrians, and vistas.

Reduction reduces the size of a tree, often for clear- ance for utility lines. Reducing the height or spread of a tree is best accomplished by pruning back the leaders and branch terminals to lateral branches that are large enough to assume the terminal roles (at least one-third the diameter of the cut stem). Compared to topping, reduction helps maintain the form and structural integrity of the tree."1

How to prune a tree - Mumby's Tree Services


Topping stresses trees and causes decay, making them hazardous and ugly. Topping is expensive in the long term as the damaged tree may become hazardous and cause damage to people or property, and may have to be removed and replaced.

See ISA Trees Are Good website for more details:

Topping is the indiscriminate cutting of tree branches to stubs or lateral branches that are not large enough to assume the terminal role. Other names for topping include “heading,” “tipping,” “hat-racking,” and “rounding over.”

The most common reason given for topping is to reduce the size of a tree. Homeowners often feel that their trees have become too large for their property. People fear that tall trees may pose a hazard. Topping, however, is not a viable method of height reduction and certainly does not reduce the hazard. In fact, topping will make a tree more hazardous in the long term.


Improper pruning (topping) of trees can be dangerous. Call an ISA Certified Arborist like Mumby's Tree Services.    Improper pruning (topping) of trees can be dangerous. Call an ISA Certified Arborist like Mumby's Tree Services.

Hiring an Arborist

“Pruning large trees can be dangerous. If pruning involves working above the ground or using power equipment, it is best to hire a professional arborist. An arborist can determine the type of pruning that is necessary to improve the health, appearance, and safety of your trees. A professional arborist can provide the services of a trained crew, with all of the required safety equipment and liability insurance.

When selecting an arborist:

  • check for membership in professional organizations such as the International Society of Arboriculture (ISA), the Tree Care Industry Association (TCIA), or the American Society of Consulting Arborists (ASCA). Such membership demonstrates a willingness on the part of the arborist to stay up to date on the latest techniques and information.
  • check for ISA arborist certification. Certified Arborists are experienced professionals who have passed an extensive examination covering all aspects of tree care.
  • ask for proof of insurance.
  • ask for a list of references, and don’t hesitate to check them.
  • avoid using the services of any tree company that
    • advertises topping as a service provided. Knowledgeable arborists know that topping is harmful to trees and is not an accepted practice.
    • uses tree climbing spikes to climb trees that are being pruned. Climbing spikes can damage trees, and their use should be limited to trees that are being removed."2

Plant Health Care (PHC) is a program developed by arborists to ensure the retainment of trees and shrubs. The objectives of PHC can be applied to single yard or to a large municipal urban forest. See ISA Trees Are Good website for more information:

1 treecare/pruning_mature.aspx


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