At the McPherson Board of Public Utilities, we understand the beauty and importance of trees in our community. They provide shade and privacy and add value to our property. Unfortunately, most power outages can be attributed to trees being too close to power lines. BPU serves over 8,500 customers who live and work along 520 miles of electric line. These are the lines that deliver power to homes, neighborhoods, businesses, and communities. We must prune the trees that are located close to these power lines regularly, on a three to four year cycle, to ensure reliable electric service.
The BPU uses a private contractor, Royer Brothers Tree Service LLC, to implement most of our vegetation management techniques and objectives. They have a Kansas Certified Arborist on staff and their employees carry an Electrical Hazards Awareness Program (EHAP) Certificate.
When it becomes necessary to trim a shade or ornamental tree away from the power lines, the trimming technique most commonly used is called Directional Trimming. Directional Trimming strives to train the tree to grow away from the wires. These practices were developed by Dr. Alex Shigo, former chief scientist with the U.S. Forest Service, and are endorsed by tree trimming professionals across the country.
A guiding principle of Directional Trimming is that 90% of interfering branches can be removed by making three larger cuts within the tree. Trimmers will look within the tree to determine where these cuts should be made, rather than simply shortening a multitude of branch tips. Trees look different initially following Directional Trimming, but this practice provides the best opportunity for the tree to stay healthy.
Directional Trimming means fewer cuts are required to remove the limb at its attachment point within the tree. While the size of the cut may be larger than is common with tree topping or rounding, fewer cuts mean better wound isolation for the tree. This translates into less susceptibility to possible decay organisms in the future.
Additionally, our crews use the collar cutting method to remove limbs. This also helps the tree to isolate or compartmentalize the trimming cut.