Trees and power lines: Should we plant tall trees under primary power lines?

By Brighton West

So in my last two posts, I talked about planting the “Right Tree in the Right Place.” This suggests we should plant small trees under lines where the utility prunes the trees away from the power lines and tall trees under lines that don’t get clearance pruning. But this means that we are planting a lot of small trees.

In older neighborhoods with big trees that have had clearance pruning, if a tree dies, it’s replaced with a much smaller tree that won’t grow into the lines. But we also know that larger trees provide more stormwater management, more carbon sequestration, more energy benefits to the adjacent property and higher property values. Big trees also do a better job of hiding the power lines. So avoiding the need for pruning costs a lot in terms of the other benefits.

Well, during the initial prunings, I’ll admit that they look kind of ugly. But with proper pruning, within about 10 years, the tree will start to grow around the power lines completely hiding the lines, and even shading out future limbs from growing into the lines. I’ve seen streets in Sellwood and Irvington where the power lines are so well hidden in mature northern red oaks, big leaf maples and horse chestnuts that you can’t tell they are there – and the street is beautiful because of this.

So the questions is:  What do you think?  Should we plant big trees under power lines, live through the “ugly pruning” phase and end up with all the benefits of large trees in 20-30 years?  Or should we continue the current approach of planting small tree under primary power lines?

West is the programs director at Friends of Trees: [email protected]; 503-282-8846 ext. 19