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Trees under power lines can cause hassle, danger
By Tony Tomeo
Years ago, I told my mother there was absolutely no more space in her garden for more trees. Unfortunately, she still wanted Lombardy poplars. I agreed to plant some if I could cut them into firewood when they became too large. The trees grew quickly, but by the time the first was ready for harvest, my mother changed her mind and the trees stayed. Now she wants me to cut a hole in the driveway to plant a sycamore, which I can cut down if it starts to raise the pavement. (Yeah, right)
Every year, I get a notice from PG&E informing me it's time for the poplars' annual maintenance. I usually call them to be certain the redwood, that was not my idea, either, is still sufficiently clear of the lines. Although more tolerant of chain saw abuse than most trees, poplars are one of the fastest growers and one of the worst choices for easement. Ironically, the letterhead on the notice reads "PG&E Vegetation Management--The Right Tree in the Right Place."
I hear many complaints about how the tree pruning crews ,who perform line clearance, brutalize trees, and I know much of their work is not done properly. However, one needs to consider the alternative. Not only can poorly maintained trees in high voltage lines cause outages, but they can be extremely dangerous. Before I continue, I should say that only trained professionals should prune trees near high voltage lines!
I am not proficient in the physics of electricity to adequately describe the obvious danger of electrical shock.
My colleagues, who are certified by the International Society of Arboriculture as line clearance technicians, studied long and hard to pass their exams.
As I look out the window at the void that was once my neighbor's pine grove, I am reminded of another hazard. Rodents that commute on utility lines have no problem jumping from trees to television cables or telephone lines. If they jump on a high voltage line, however, they form a circuit. Unless the specific rodent is an extremely good conductor, it is instantly electrocuted and falls, often flaming, to the ground. Although some might find this amusing, it can easily start fires, as with my neighbor's pines.
Abusive "hacking" is often necessary for line clearance. In most situations, the improper cuts or stubs are not done intentionally, but simply because the priority is to clear the lines. PG&E cannot always justify spending extra time and resources on proper pruning. It is often necessary to get an arborist to correct damage after clearance crews finish. For example, my poplars usually get their tops cut off at this time of year. In winter, I finish trimming them and dress the wounds left when topping by cutting them properly.
The best way to avoid problems with line clearance pruning is to use "the right tree in the right place." Poplars are certainly not the right tree. Smaller trees that are below the lines at maturity are the best choices. Vertical trees with central trunks, such as redwoods, may have limbs reaching toward electrical lines removed without causing too much damage if the trunk is at a sufficient distance to continue up past the lines. Unfortunately, redwoods under lines need to be topped and never develop as they should.
Palms are probably the worst choices. The Mediterranean fan palm is the only commonly planted palm that stays low enough to not cause problems. All others eventually reach the lines. Unlike "real" trees, palms cannot be pruned down. They only have one terminal bud each. If it is removed, the tree is dead.
Tree of the Week: Bunya-Bunya
This certainly is not "the right tree." However, there are a few of them around and I often get questions about them. The bunya-bunya, Araucaria bidwillii, commonly called the monkey puzzle tree, is one of the boldest of trees. Because not many have been planted since the Victorian period, almost all are large and old. Although still not commonly available, new specimens have been appearing in contemporary landscapes. They may be kept in containers for many years, but are not very impressive as small trees. At maturity, they get to 80 feet tall, so are best used in large spaces. Their foliage is more than "prickly"--it is downright dangerous. The small scale-like leaves are rigid and sharp. The cones are also potentially dangerous, weighing up to 15 pounds! Bunya-bunya trees are very interesting, but are best appreciated from a distance.
Horticulturist Tony Tomeo can be contacted at 408.358.2574.
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Los Gatos, California Since 1881
This prehistoric-looking 'bunya-bunya tree' towers over the lawn at Saratoga's Villa Montalvo. Due to sharp leaves and heavy cones, these trees are best admired from afar.
