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How to choose a qualified arborist

November 13, 2015
Martha Proctor

A tree that has taken decades to grow can be destroyed or damaged in minutes by an inexperienced or unqualified arborist. To enable the trees on your property to stay as healthy and attractive as possible, careful attention should be given to their planting and care.

Well-maintained trees add beauty, structure and shade to any garden, park or urban site. Even more important, through photosynthesis, trees absorb carbon dioxide; this process removes and stores carbon while releasing oxygen, the gas vital to sustain human life, into the air. Trees provide habitat to birds and other wildlife and help to prevent soil erosion. Trees buffer wind and noise. Trees reduce the cost of cooling in summer and heating in winter. It’s estimated that trees add between 2 percent to 5 percent and sometimes more to the value of property. Annuals are replaced yearly, perennials every few years but trees can represent a lifetime investment of time, nurture and nature.

Although trees are incredibly resilient, they can be severely injured by improper planting, pruning, fertilization or pesticide treatment. Also, as with any plant, trees are susceptible to damage or injury from diseases, insects, pollution, damage to roots, trunks or leaves and from poor tree-care practices. A certified arborist can improve the aesthetics and health of a tree while maintaining its value and protecting it from threats.

Choose an arborist who has the proper training for the job to be performed. California does not require that arborists be licensed with the state, but many states do. The next best check is to find out if the arborist is certified by the International Society of Arboriculture (ISA) by going to the ISA website, www.isa-arbor.com, and navigating to “Find an Arborist.” This certification means individuals have passed a written competency exam, have had appropriate training and work experience and must participate in continuing education programs to maintain their certification.

Other important ways to ensure that the individual you hire isn’t just someone who has a truck and a chain saw include:

• Get three quotes from arborists you have pre-qualified and then select the one you feel will give you the best service and value. Keep in mind that the company with the lowest bid may not be the best choice.

• Ask for certificates of insurance, including proof of liability for personal and property damage (including your neighbor’s), and workman’s compensation. To be sure that the insurance coverage is current, check with the insurance company and get a copy of the insurance binder naming you as the insured. You may be held financially liable if an uninsured worker is injured on your property or damage is done to a neighbor’s property.

• Be wary of people posing as qualified arborists who knock on doors because they happen to be in your neighborhood. Most reputable companies have a physical address for their business. If you ask an arborist if he tops trees or uses tree climbing spikes when pruning trees and the answer is yes, you’re probably dealing with an unqualified individual.

• Ask for local references and, if possible, talk with former clients. Experience, education and a good reputation for meeting client expectations are signs of a good arborist.

• Obtain a written contract that details the scope of the work to be accomplished (including the chemicals to be sprayed and their environmental impact) and the total dollar amount for that work so that you know the cost and exactly how much work is planned. Never pay in advance.

Tree work can be surprisingly expensive. Ask the arborist if conducting the work during the winter would be cheaper. Also, combining the work on your property with that of a neighbor’s may reduce cost.

Landscape trees are valuable assets to your property and your community. Well cared-for trees can provide benefits valued at three times their costs during their life span. Your “good care” is best provided by a professional arborist.

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