No matter how you look at it, trees and power lines don’t mix. There are a lot of careful considerations arborists must make when planting new trees in proximity to power lines and other infrastructure poles for things like telephone and internet. Here is how this important municipal need went into planning the Shelby Avenue Arboretum and actually planting the trees to best prevent headaches in the future.
In a city, the municipality has the right of way along the road for several feet, and just how much depends on a city’s needs and other logistical factors like sidewalks. The company working in much of Nashville is NES, or Nashville Electric Service, and their right of way exists alongside every road in the city. NES maintains their power lines with periodical tree trimming in order to prevent power outages that result from fallen tree limbs. While not every outage is linked to fallen branches, a majority of them are caused by trees in proximity to power lines. Fallen branches can’t be eliminated completely, as wind and other weather factors can cause healthy limbs to fall. However, pruning and removing unhealthy or dead limbs and trees can greatly reduce the number of outages that a city faces.
It’s the responsibility of the power company to maintain trees and limbs in most circumstances, though when planting new trees, that responsibility does partially come down to the person or company actually growing the tree. It’s important to consider how a tree’s canopy and height may impact power lines, even decades in the future. Having a solid idea of how a tree will grow is possible with a little research. It’s not only helpful for maintaining a city’s electrical infrastructure, but it also makes sure the tree will have the healthiest possible life. While chances are city tree trimmers won’t harm the tree by trimming it, its shape can be drastically altered if it grows into a right of way. In order to avoid removing a tree, trimming can become unsightly. That’s because it’s far more important to avoid contact with power lines than allow a tree to grow to its full potential. This is an unfortunate life for a tree, and it often leads to an eyesore for the community. Avoiding issues like this years down the line comes down to careful planning, and arborists are well-versed in making sure things work going forward.
When Shelby Avenue Arboretum was in its first stages, tree removal was an important focus for planners. Many of the trees removed along Shelby Avenue posed threats to power lines and utility poles. There were many ash trees on the projected path of the arboretum, and they were removed for two main reasons. Ash trees can easily grow to a height of over 35 feet, making them a major threat to power lines. Additionally, ash trees are highly susceptible to the emerald ash borer beetle. This invasive beetle species has been responsible for the deaths of millions of ash trees in the U.S. already. By removing these ash trees, we prevented the spread of these insects in the city and minimized the potential for damage from these trees in the event that they were diseased. Unfortunately, this disease is an inevitability for many trees. Removing them uncomplicated the ecosystem and made sure that power line damage was minimized.
Most of us view power outages as big inconveniences — at best, they’re an excuse to read a book by candlelight, but there’s a lot more danger that can result from a limb on a power line than some boredom. How dangerous are downed power lines from tree limbs? Fallen limbs and lines can obstruct roadways, preventing emergency services from accessing homes and attending to calls. Beyond that, live wires pose lethal threats to anyone who may be close to them, both as they fall and afterward. Electric lines carry a great deal of electricity, and live wires can spark fires, destroy cars, and spread via groundwater far beyond where the wire terminates. Active wires can ignite trees or kill them completely, because trees are mostly water. Some people who rely on electricity to power life-maintaining or life-saving medical devices like oxygen machines or dialysis. Without electricity, people who need this care are forced to travel for the services, but travel isn’t always possible. Elderly people or folks with a reliance on these medical devices can die if power is not restored quickly. During hot summer months or cold winters, cooling and heating homes becomes a major problem. Without heat in the winter, pipes can freeze and burst in homes and other buildings, causing significant damage. In rare cases, people can die from exposure to extreme cold during severe winter storms. In the summer, heat stroke can be deadly for anyone, but especially the elderly, children, and the immunocompromised.
Every risk to the safety of the city’s public needs to be considered and planned for. Whether you’re planting trees or trimming the limbs of existing trees, it’s important to be on the lookout for possible danger zones. The Shelby Ave Arboretum is a city arboretum nestled in the heart of Nashville, Tennessee. Our mission is one of education, preservation, and beautification, but it’s also heavily focused on providing safer streets for the people who use Shelby Avenue on their commutes or call it home. For visitors and residents alike, Shelby Avenue Arboretum is a reflection of this neighborhood’s strengths.
So can you plant trees under power lines? Yes, absolutely! When planning Shelby Ave. Arboretum, we had to be careful in selecting an area of roadway that had ample room for trees. Not only that, but these trees needed to be easily accessible for people to see. A sidewalk provides us with more room for planting than roads without any walkability, giving us the space to plant our trees safely away from power lines. There are some restrictions to choosing trees for a roadside arboretum. The trees used need to have canopies that provide shade to pedestrians but not obstruct drivers’ visibilities. Obviously, the other primary concern is that the trees don’t grow tall enough to reach the power lines. There are many trees that don’t reach the height of lines and transformers, which are usually at least 30 feet off of the ground in areas with a sidewalk and pedestrian access. This does limit which trees are suitable for a project like Shelby Avenue Arboretum. But that doesn’t mean our trees aren’t diverse in canopy size and height, however. Let’s take a look at some of the power line-appropriate trees we’ve planted and are planting right now.
Many redbud species are well-equipped for being planted near power lines, because they reach a height of around 30 feet at most. Many cultivars like the burgundy hearts redbud only reach a maximum of 20 to 25 feet. Mature redbud trees will grow to below the lines on Shelby Avenue, but at a respectable and impressive size nonetheless.
Shelby Avenue is home to a variety of Japanese maple trees, which are also optimal for roadside growth, rarely reaching above 25 feet in height. Some have made it to 30 feet, but with some minor trimming, they healthily grow alongside power lines and roadsides.
In addition to the considerations made for power lines, other safety concerns were at the forefront of planning Shelby Ave. Arboretum. No trees were planted within 30 feet of any of the intersections along the arboretum to preserve line of sight for drivers and pedestrians alike. This is a very conservative distance for planting trees near intersections, but safety is a big part of what we do. In all aspects, Shelby Avenue Arboretum is focused on creating a safer, more beautiful street in our great city. Ensuring that vital services like electricity and internet services are secure is just another part of developing and supporting a roadside arboretum.
Do you want to learn more about what we’re doing at Shelby Avenue Arboretum? Want to volunteer or simply visit and learn more? We are happy to have the public tour our project and explore, learn, and grow closer to nature. Our commitment to safety extends from our love for nature and the natural urge to experience the outdoors everywhere, even in the heart of a city. Whether you’re planting trees of your own or simply want to learn more about how we are keeping our trees from damaging power lines, feel free to give us a call to learn more.
The Shelby Avenue Arboretum is a community-grown project led by Nashville Tree Conservation Corps and is in partnership with NTCC and Metro Nashville.
Nashville Tree Conservation Corps
PO BOX 60683
Nashville, TN 37206
