UNITED STATES—Last winter was a doozy! It involved historic frost, snow, rain, wind, floods and mudslides. A few roads remain closed in some regions. Major electrical outages were too numerous for prompt repair. Weather alone did not cause such outages though. It merely dislodged vegetation that did so. This demonstrates the necessity for utility clearance maintenance.
Utility pruning is a specialized but very often unpleasant sort of arboriculture. It maintains necessary clearance between vegetation and utility cables. Its unpleasantry derives from its harsh efficiency. Clearance is the priority. Proper arboricultural technique is not. There is no compromise. Trees that encroach too closely to cables are likely to regret doing so.
Proper arboricultural procedures are too expensive to justify for utility clearance pruning. Otherwise, electricity and other utilities that utilize cable would be much more expensive. Besides, for many trees within utility easements, proper arboriculture is impossible. They cannot accommodate necessary pruning without disfigurement. Several cannot survive such disfigurement.
Selection of new trees should accommodate utility easements.
Palms, for example, cannot survive without their single terminal buds. They lack limbs to divert growth to. Removal of a terminal bud that encroaches too closely to utility cables is lethal. Palms generally grow only upward. Those that grow tall rapidly cannot live below utility cables for long. Very few palms remain low enough to maintain minimal clearance.
Excurrent trees are generally more vulnerable to disfigurement than decurrent trees. The single central trunks of excurrent redwoods and spruces do not adapt to redirection. The several main limbs of decurrent oaks and elms are more cooperative. Compact trees that are unlikely to reach cables are least problematic. Of course, many trees are unplanned.
Arborists can repair some minor clearance pruning damage or disfigurement. They might prevent some damage by timely pruning for containment. Unfortunately, some damage is neither repairable nor preventable. Also, such procedures are too dangerous for anyone who lacks qualification for them. Typical garden enthusiasts must avoid electrical cables!
Highlight: Coast Live Oak
Valley oak and coast live oak are the two most magnificent oaks of California. Valley oak likely receives more notoriety. It stands taller and defoliates to expose its sculptural form through winter. Coast live oak, Quercus agrifolia, is almost as grand within its evergreen foliage. It can grow as tall and broad as 75 feet, with trunks wider than 10 feet.
Coast live oak is notably variable in the wild. Exposed and solitary trees can grow bigger and older than grove trees. They can live for many centuries and hang their canopies to the ground. Grove trees may not live half as long and tend to shed shaded lower growth. Solitary trees are likely to survive fire. Grove trees within forests are less likely to survive.
Coast live oak is more appealing in the wild than within home gardens. Regularly messy debris is mildly herbicidal to some delicate plants below. It also stains hardscapes. Trees that matured without irrigation are very susceptible to rot with new irrigation. Landscapes around such trees must therefore demand very little. Roots are very sensitive to damage.
Tony Tomeo can be contacted at tonytomeo.com.