When trees are large, damaged or overgrown, they can cause significant hazards to safety and property, particularly if they are within range of power lines or other utilities. When they have not been properly pruned, it is easy for branches and foliage to fall on power lines and damage them. Power line damage can lead to power outages, but a downed power line is a significant safety hazard.
To ensure that your tree is not a danger to power lines or other structures in a utility right-of-way, an arborist hired by your utility company will prune limbs in a way that is both safer for power lines and better for the overall health of your tree.
The Need to Remove and Trim Trees Near Power Lines
When trees become overgrown or diseased, they can lean on power lines. Sometimes there is even soil erosion beneath a tree that can cause it to tilt and become unstable. Trees that have impacted lines will often have scarring on the trunk and branches. In fact, most trees that grow large — 40 or more feet in height — should ideally be planted 50 or more feet away from the right-of-way and any power lines or cables. However, many trees were planted years before such restrictions were in place, or they grew from self-sown seedlings. For this reason, arborists are often called in to prune trees in both residential and commercial areas to keep power lines — and people — safe.
The Old Way to Prune
In fact, compared to other methods such as topping, stubbing or pollarding, directional pruning is better for the protection of the tree’s health. Directional pruning is the accepted industry standard endorsed and promoted by the National Arbor Day Foundation and the International Society of Arboriculture.
In the past, many utilities practiced “tree topping,” which is also known as Stubbing or Pollarding. It is called topping because, in the finished product, the tree’s topmost branches resemble a straight hedge, much like you might have in front of your home. In topping, the tree’s crown is cut down to rest below any power wires, making it a very rapid way of managing multiple overgrown trees. However, this method leaves many branch stubs on the tree, which typically produce sprouts before the branch rots below the cut of the stub. In just a few years, these sprouts will grow back up into the power lines and the weakened, rotted branches further impact the tree’s health, increasing its potential to become a hazard. Clearing must be done again and again each time the tree is further weakened until it ultimately must be removed.
Directional Pruning: Healthy and Cost Effective
In fact, compared to other methods such as topping, stubbing or pollarding, directional pruning is better for the protection of the tree’s health. Directional pruning is the accepted industry standard endorsed and promoted by the National Arbor Day Foundation and the International Society of Arboriculture.
Many arborists today prefer directional tree pruning, also known as the Shigo method. In this technique, the arborist will only prune the branches that are growing toward lines. Branches that are naturally growing away from the wires will be left to grow in their natural pattern. And because branches are cut only where they connect with another branch, no stubs are left so that pruning cuts heal and reduce the incidence of branch rot or weakening.
In Shigo pruning, cuts are made specifically to avoid harming the bark ridge of the branch and the branch collar and to reduce flush cutting. Flush cutting makes much larger tree wounds that can cause significant decay, leading to branch dieback. Arborists concentrate on ensuring that any branch left after cutting is, at a minimum, one-third of the diameter of the pruned branch to ensure that it is healthy and not prone to sprouting.
When an arborist uses the directional pruning method, the trees will often have an asymmetrical or unbalanced look at first. Many form a distinctive “V” shape, while others look more like the letter “L.” Ultimately, trees pruned using this technique will grow to fill in the lopsided silhouette and remain healthier.
When a Tree Can’t Be Pruned Directionally
As we mentioned earlier, some trees were planted long before there were restrictions. Many of these trees have been “topped” several times or more. These trees are often in such poor condition that they cannot be pruned using the directional method and instead must continue to be topped or even removed. Some trees with narrow crowns like conifers are difficult to prune directionally, although it can be done. In most cases, trees that do not respond well to directional pruning will simply be removed and if the utility agrees it could be replaced with a tree that is a better fit for the right-of-way.
Your Arborist NG Gilbert Services, Townsend Tree Service LLC Knows the Right Way to Prune Trees Correctly
Arborists and Line clearance professionals are certified professionals that understand the right way to prune a tree correctly — even if the aesthetic looks a little strange at first. Directional pruning, as opposed to topping, can help remove hazardous limbs from interfering with power lines while ensuring that the health of the tree is kept in mind. So, if you are wondering about those young, weird-looking trees lining the streets of your town, just be patient. They will eventually grow into beautiful, sturdy, healthy, specimens while ensuring that the integrity of your power system and public safety is assured.
Townsend Tree Service and NG Gilbert are leading, multi-state providers of expert tree trimming, line clearing, and vegetation management services. Click here to learn more about how our pruning professionals help keep power lines—and the public—safer.