
Cornwall Electric is dedicated to bringing its customers the most reliable and efficient electrical service available. One of the ways we accomplish this is by integrating a professional tree trimming program into our daily operations.
Cornwall Electric's Tree Trimming Program is intended to help protect the public, protect property and maintain electric reliability. Cornwall Electric implements accepted professional standards for the pruning of trees near power lines. This program provides safe, reliable and inexpensive electricity. We must keep trees that are located near power lines pruned on a regular cycle. We trim trees a certain distance away from the power lines to allow for growth until the trees are trimmed during the next cycle.
Many service outages and interruptions are caused by tree limbs which fall into power lines causing damage to wires, short circuits and other problems. That creates potential danger for you and your property, danger that can be avoided by not planting tall growing trees under or near electric wires, and by routine tree trimming.
Cornwall Electric adheres to the American National Standards Institute (ANSI) A300, Standard Practices for Trees, Shrubs and other Woody Plant Maintenance. This standard (endorsed by the International Society of Arboriculture, the National Arbor Day Foundation and the Utility Arborist Association) requires treetrimmers to cut branches back to the “parent limb”. This practice allows the pruning cuts to “heal” more rapidly, reducing the chances of insect and disease damage, and promotes a healthier re-growth of branches that are directed away from the power lines.
Pruning considerations include species of tree; growth and re-growth rates; location of trees in proximity to power lines; voltage of power lines; types of power line construction; length of pruning cycle; natural tree shape and branch patterning; general tree condition; appearance after pruning.
The following priority is followed in determining when and where tree trimming will occur:
- Reports of electrical outages caused by trees.
- Areas where trees have been damaged by storms.
- During the regular tree-trimming cycle (approximately every three years).
- Periodic inspections by Cornwall Electric personnel.
- Reports from customers indicating potential tree/power line problems.
What We Do
Cornwall Electric uses the “natural trimming” method endorsed by the Tree Care Industry Association. It is called natural trimming because branches are pruned back to a natural point of growth in the crown of the tree. Natural trimming is healthier than tree “topping”, which is the indiscriminate cutting back of tree branches to reduce the size of the tree crown. According to the International Society or Arboriculture, although topping generally leaves the tree with a more uniform or balance appearance, topping stresses trees, making them more vulnerable to insect and disease infections and causes decay. To assure that proper tree trimming and removal is performed, Cornwall Electric contracts with professional line clearance tree trimming firms. These firms are required to maintain “line-clearance tree-trimmer” certification by the Province, be licensed to work in Cornwall Electric’s service area, and adhere to all standards, guidelines and laws governing the performance of tree work.
How You Can Help

Customers can help reduce costs and maintain a pleasant environment by ensuring trees of the right type and size are planted near power lines. Remember “Right Tree, Right Spot”. Seek permanent solutions. Do not plant trees near electric lines; or plant only low-growing, compact varieties. The guidelines given here aim to reduce sprouting, reduce the working time in a tree for the tree worker, increase the time between pruning cycles, and help the trees planted near lines to be healthy, safe and as attractive as possible.
It is better for the trees, lines and customers to remove fewer but larger branches at nodes. Nodes are where branches shed naturally. It will take time to make all the adjustments given here. But if we all work together, the adjustments will come. And the public, customers, property, trees, and tree workers will all benefit.
Types of Tree Trimming
Below are illustrations of the types of trimming that Cornwall Electric performs. The style used depends on how the tree is placed in relation to the power line and the type of tree that is being trimmed.

V-out (crown reduction) - in V-cutting, branches are pruned back toward the center of tree crown.

Side - side-trimming prunes back branches on the side of the tree.

Notch - notch-trimming prunes branches to create a “notch” in the upper tree crown so power lines can pass to the side and above the tree.