Hiring an arborist is a decision that you should not take lightly. Tree work performed incorrectly not only poses a risk to the tree itself but also endangers the person performing the work. An unqualified person may not have proper insurance, leaving a liability burden to the customer that could run into thousands of dollars. Put a professional to work for you and your trees!

Hire a tree care company that is bonded, licensed, and insured.

Some states require registration by tree care companies. Registration is not, however, a guarantee of quality. Some communities also require arborists to be licensed to work within city limits. You should always check with local agencies to see if licenses and/or permits are required.

Ask for ISA Certified Arborist credentials.

Current membership in professional organizations such the International Society of Arboriculture (ISA) demonstrates a commitment to quality by the arborist as well as a dedication to keeping up-to-date on research related to trees and tree care. ISA Certification indicates the individual has passed ISA's extensive examination on all aspects of tree care and maintenance.

PNW-ISA maintains a For Hire ISA Certified Arborist Directory of ISA Certified Arborists who serve in Alaska, Idaho, Oregon, Washington, and British Columbia. The searchable database allows you to locate commercial tree care companies and consulting arborists who can help provide the best possible care for your trees.

Ask for references and check them.

Select a company or individual with a proven track record of good and ethical work practices. Remember, you are hiring a "doctor" for "preventive care" for your trees; make decisions as thoughtfully as you would for your own health care.

Get bids or estimates from more than one tree care firm.

Examine the credentials of the firm and the staff who do the work, as well as the written specifications of the submitted bids. Determine which bid has the best combination of cost, scope of work, skill, and professionalism. Your investment in your trees rests in the hands of the tree care company. Make sure the arborist or firm you hire is knowledgeable and reputable.

Don't rush into a decision because you are promised a discount.

Be sure you understand the work to be done and the cost of the services. Don't pay in full before the work is done; reputable arborists will rarely ask for payment up front.

Avoid arborists who recommend excessive pruning.

Knowledgeable arborists rarely recommend topping a tree or other drastic pruning practices that might injure trees or make them hazardous. Reputable arborists more commonly recommend various options to address tree conditions and situations. Avoid any firm or individual who advertises tree topping or view clearing or suggests such practices.

NEVER allow a tree worker to climb your trees using spikes or spurs.

Tree-climbing spikes or spurs cause wounds in trees and open a pathway for diseases and insects, potentially weakening or killing the tree.

Beware of door-knockers, flyers, or cold calls.

Reputable firms rarely try to acquire work in this fashion. Remember you are hiring a health care practitioner for your trees. Would you hire a dentist from a cold call? Or a surgeon who left a flyer on your windshield? The same attention to hiring a knowledgeable, reputable tree service will ensure your trees get the care they need to remain safe, sound, and beautiful over a long, healthy lifetime. Improper tree care practices can damage trees, possibly causing a tree to become hazardous or even die.

Be willing to pay market rates.

Proper tree work is not necessarily inexpensive. Reputable arborists are licensed, bonded, carry insurance, and maintain expensive, specialized equipment. Beware of exceptionally low estimates, which may have hidden costs and/or indicate an arborist lacking professional credentials.