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Ask An Arborist

What IT geeks are to computers, certified arborists are to trees


Boise Weekly asked me to write about certified arborists and I am proud to say that I am one. My GPA is admirable, but the CA's test is among the most difficult I've taken. This certification is offered through the International Society of Arboriculture. Applicants must have either a four-year degree in a related discipline, or three years of practical field experience. I cited the latter, and halfway through the three-hour ordeal realized I was five to 10 years short.

I had nearly memorized the study guide, but the questions seemed to have been composed by Dickens or Tolstoy, writers with proclivities for lengthy sentences of qualifying clauses. An example I remember well: If a tree which has no signs of borers has defoliated extensively on the south side, is dripping a substance that smells like dishrags and corrodes metal, and is poised precariously over the playground at a busy park on the north end of a stagnant pond, the likelihood that it will fail at a stress point between the first and second crotch of the scaffold branches is greater than the circumference of the trunk below a woodpecker's tracks. True or false? ("Crotch" is an important word in the arborist's vocabulary; one of my esteemed male colleagues still giggles through training sessions.) I did very well on some parts of the exam, but needed remedial work on lightning rods and cables that don't terminate in clotheslines.

Certified arborists provide many important services in a tree-loving community. Utility arborists are trained to work safely near power lines, clearing branches that may interrupt the flow of electricity to freezers full of venison, coffee makers and hair dryers. When I worked as a notifier for Idaho Power, I encountered many amiable individuals who were unhappy about having their trees trimmed into the shapes determined to be least harmful to the tree. The perfectly done-up ladies heard "hair dryer." The macho guys with gun racks got the freezer references. Putrid meat and bad hair are meaningful images.

There are many firms in the area that perform perfectly lovely tree trimming. It's not difficult to see where they've been, as opposed to hatchet jobs such as one recently committed by a well-meaning neighbor on a pear that overhung the sidewalk. Trees do benefit from careful and disciplined pruning conducted by trained professionals with rational objectives. I'm trained to direct pruning protocols, but my name should never appear in a sentence with "chainsaw." Be absolutely certain that a company you've invited to shape your trees has the certification that signifies true know-how.

Trees and humans have many similarities. Trees develop character on the basis of their genes and environments. Their resilience is proportionate to the challenges they face in their early years. Environmental stress weakens their immune systems and they have a complex vascular structure that must function satisfactorily in order for them to thrive. They may wheeze and malinger if they've been damaged, and steadily lose their beauty and vigor. Many people confuse a desire to save dangerous and unsightly trees with a love of nature or respect for ecosystems. They're often running for office.

There is nothing natural about the way we live, and only a certified arborist can predict, with the help of a crystal ball, whether a tree intends to crush your home or vehicle. Consulting arborists are asked to determine the advisability of retaining trees in construction sites and the steps to be undertaken for their comfort. Age and species are important factors, but it is not without regret that arborists condemn trees that have outlived "safe and useful life expectancies." A tree is no less likely to fall on the people who override these judgments than upon those who write their death warrants. Statistics have shown, however, that '68 Chryslers are more likely targets of branch failures than Mini Coopers.

Appraisals are another domain of certified arborists. Documents prepared by professionals have more credibility in damage claims and acquisition compensations. Beeches, for example, have a higher species rating than willows, and an assessment that doesn't cite district guidelines and standard practices isn't likely to prevail in court or domestic disputes.

Many lawn care companies are in the tree business. They spray everything often. Some of them drill trees for scale, aphids, poor color, wet bark, or things we arborists may not perceive. Concrete contractors assure property owners that severing major roots for a driveway is a harmless practice. The cable guys sometimes wield a chainsaw, and roofing workers perform routine surgical procedures on offending limbs.

You don't have your hairdresser defrag your hard drive, nor would you give financial advice to the geniuses who trust that our national deficit is sound policy. You may know in your heart that crabs are beautiful in a landscape and troublesome in crotches, but an arborist you're not. Trees mitigate pollution, provide shade and look dandy when they're not resting on the roof. They deserve the attention of professionals who have been trained to evaluate their needs, monetary value or problems. Now step away from the chainsaw, put your hands over your head, and walk to the phonebook.

Linda Jarsky is an advanced master gardener, certified arborist and landscape designer, and marketing director for DG Nursery and Turf.