Horridculture – Opposite Poles

P90904This is not about North and South. It is about a utility pole and a pole that remained from a redwood tree that was too close to it. One is there to support a variety of cables and a streetlamp. The other just wanted to grow into a redwood tree to join the rest of the forest. One has been deceased for many years or decades. The other was alive just recently, but is now only a stump.

The picture above shows how many cables the utility pole supports, as well as the streetlamp. When I did my internship in 1988, the arborists whom I worked with knew what each of the various cables were for; high voltage, lower voltage, cable television, telephone and whatever else was up there. Fiber optic cables have since simplified the telephone and television cables.

The picture above also shows how the unfortunate redwood tree needed to be cut back for clearance from the electrical cables. I was mortified to see this so prominently visible on the edge of a main road, because I should have noticed the problem earlier and just cut the tree down. Not too long ago I was pruning many other redwood trees for clearance from other streetlamps.

Those who pruned it instead, along with any other trees that were encroaching into the electrical cables, were very efficient with establishing clearance, but not so proficient with aesthetics. Obviously, I could not leave this tree like this on the side of the road. Even if I did not care what it looked like, I did not want it to regenerate and immediately encroach back into the cables.

The picture below shows my corrective pruning. The stump is certainly not dead, and will try to regenerate, but will be easier to keep down. If kept down long enough, it may eventually die.

The second picture below shows the stripped trunk in two sections that are nearly eight feet long, and a short bottom section that is a bit more than two feet long. The two long sections are straight enough for gate posts (although there is another plan for them). It is a sad demise for the formerly healthy and sound redwood tree, but became necessary to keep the electricity on.P90904+P90904++



P90629KKIncandescent light bulbs were the standard form of electric lighting for more than a century after their invention. It took a while for fluorescent and halogen lamps to become popular; and by the time they did, high intensity discharge (HID) lamps had already become available. Nowadays, light emitting diode (LED) lamps seem to be replacing all sorts of electric lighting.
For a brief time in the late 1980s, high intensity lamps that were being used for large scale applications and street lamps became a fad for exterior household lighting. They worked nicely for driveways, so many of us believed that they would work just as nicely for night lighting of home gardens and patios.
By that time, most of us had realized that the sickly yellowish glare of the sodium vapor type of high intensity lamps that were so common as street lamps was not at all appealing around the home, and was downright unflattering for foliage and flowers in the garden. Mercury vapor high intensity lamps became more popular for such applications instead, even though their slightly bluish bright glare is no more inviting.
During this time, while the renowned landscape designer Brent Green and I were still studying horticulture at Cal Poly in San Luis Obispo, his father had a rather fancy mercury vapor lamp installed in his backyard.
Of course, Brent was furious! He had put so much effort into cultivating a remarkably inviting outdoor living space, only to have it illuminated at night like an industrial warehouse. When turned on, the lamp made a constant buzzing hum. It hung from a wall like a big glowing paper wasp nest. Brent referred to it at the ‘beehive’.
The quality of light produced by modern electrical light sources has fortunately improved since then. Nonetheless, contraptions such as this street lamp suspended on an otherwise exemplary ponderosa pine are not easy to warm up to.

Trees Need Clearance From Utilities

30320thumbPalm trunks grow in only one direction; upward, toward sunlight and away from gravity. Each trunk is equipped with only a single terminal bud. If that bud encounters an obstacle, it can not be pruned around it. Palm trunks that get get too close to high voltage cables, or that might sway too close with a breeze, must therefore be removed to maintain minimal clearance from the cables.

Queen palms are notorious for getting planted under high voltage cables because they are so often impulse purchases that get planted without much planning. They are popularly planted along rear fences, exactly where high voltage cables are often located. Mexican fan palms often grow along rear fences as well because that is where birds and rodents are likely to drop the seeds.

Trees with single central leaders, like redwoods, spruces and certain pines, will be disfigured if their main trunks need to be topped for clearance from cables. Removal of such trees is often more practical than this sort of disfigurement. More extensively branched trees like sycamores, ashes, oaks and elms, are more adaptable to clearance pruning if it is not too severely disfiguring.

It is much simpler to not plant trees that get too large under high voltage cables. Elsewhere in the garden, where there is enough lateral (side) clearance, vertical clearance is not such a problem for larger trees. Small trees like redbud, purple leaf plum, photinia and various pittosporums, either do not get tall enough to reach upper cables, or will require only minimal pruning for clearance.

Below high voltage cables, the lower cables are for lower voltage, telephone and television. ‘House-drops’ are the cables that extend from utility poles to houses and other buildings. Although clearance is not so important for these lower risk cables, limbs that lean on them and blow around in wind can be abrasive. Sagging limbs can cause utility cables to sag more than they should.

Unfortunately, those who prune trees for utility clearance are efficient, but rarely arboriculturally correct.

Easements Really Should Be Easier

70802thumbLike Michael Jackson said, “You got an easement on down the road.”. . . or something like that. In older neighborhoods, that is where the utility easements are usually located. These are zones for utility poles that suspend electrical, telephone and television cables. When electricity first became available, that was the easiest place to put the cables, and the practice continued for decades.

Utility easements in middle aged neighborhoods are usually at the rear boundaries of back yards. They were put there to get out of the way of shade trees in front yards, particularly street trees. Where there are alleys in back, easements are on one side of the alley or the other. The same applies to narrow streets with easements. More modern neighborhoods have subterranean utilities.

Those of us who must contend with easements know how difficult they can be. Trees that encroach too closely to the high voltage cables on top of the poles must be pruned for clearance, even if such pruning disfigures or kills them. Lower cables for telephone and cable television sometimes get tangled with vines or big shrubbery because clearance from vegetation is not such a priority.

Utility providers have access to easements to maintain their systems. So do the tree services that have the grim task of pruning encroaching vegetation for clearance from high voltage cables. They do what they must to maintain reliable service; which is unfortunately not always compatible with what we want for our trees. Clearance pruning is too often unsightly, but it is very necessary.

The only way to avoid unsightly and disfiguring clearance pruning to to only plant trees that will not encroach into high voltage cables. Of course, in small gardens with big easements, the choices of trees that stay proportionate to available space are very limited. Except for Mediterranean fan palm or palms that stay very short, palms should never be planted below utility cables. They grow only upward, and can not be pruned around cables, so must be removed when they get too close.