The directional method of pruning trees approved by the National Arbor Day Foundation and the International Society of Arboriculture is utilized by Bay City Electric Light and Power.
Directional, or target pruning, removes only the limbs that will come in contact with energized conductors. It removes branches at a joint, or lateral, of a limb, where the tree would be likely to lose a branch under natural conditions.
At this lateral, the tree's natural defenses protect against disease. Directional pruning also reduces the number of times the tree must be pruned. By directing growth away from the power lines, it allows the tree to as closely as possible achieve its natural height and shape.
Other methods of pruning, such as round-over or topping, cut tree limbs back to stubs or small branches, eliminating foliage and buds that contain next season's growth. Round-over and topping can weaken trees and make them less resistant to pests, while destroying their natural structure.