Column: Only certified arborists are experts |

Column: Only certified arborists are experts

by JoAnne Skelly

Can you reach all the tree branches you need to prune from a six-foot ladder?

If not, it’s time to call an arborist. An arborist is a tree specialist. Becoming a certified arborist requires three years of experience in arboriculture or two years’ experience and a college degree in a related field.

A certified arborist must pass a lengthy test which includes identifying trees, pruning techniques, tree health, and more. A certification is good for three years as long as the arborist continues to study and attain the required continuing education credits.

The certification is usually issued by the International Society of Arborists. A certified tree worker /climber specialist must have 1-1/2 years’ tree climbing experience and pass a test on climbing, knots, safety issues, pruning techniques and tree biology.

There are many tree pruners out there who are not certified. University of Nevada Cooperative Extension only recommends certified arborists and each office has a list of certified arborists or certified tree workers. The education these people have attained means you should get good care for your trees.

Of course, a certificate can’t guarantee quality, but your chances are a lot better with a certified professional.

Consult a certified arborist before cutting tree roots to put in a new sidewalk or before doing any other construction work which might damage roots. Root damage may allow infections to enter a tree, reduce roots that can absorb water, or decrease the structural integrity of a tree. It may fall over!

Certified arborists can prune trees to provide better structure or to get branches away from wires. You don’t want to work near any power lines. It’s very dangerous. Arborists can also fertilize trees, do pest control (with the appropriate pesticide applicators’ license), diagnose tree problems, provide lightning protection systems or install cabling and support systems between forked branches and trunks.

Rarely will a good arborist recommend topping a tree. Topping creates hazardous trees and destroys the health of a tree. Topping is not a recommended or accepted pruning practice by informed tree care people. If the top of a tree is dead, it does need to be cut out or the tree needs to be removed.

A conscientious tree worker will not use climbing spikes unless removing a tree, as they create areas for infection and disease in a tree. Beware of a tree person who eagerly suggests removing a living tree – that is a last resort. Usually a certified arborist will not also sell firewood!

Beware of tree cutters who go door to door. A certified arborist stays pretty busy and probably won’t be knocking on doors to get business. Ask to see their certification card. Ask for certificates of insurance, proof of liability coverage for personal and property damage, and proof of workers compensation.

Check with the insurance company to make sure the insurance is current. Find out ahead of time what work will be done and how much it will cost. Get a contract that specifies a start and end date, details exactly what will be done, and includes cleanup. If a tree is removed, will the stump be ground out and surface roots removed to one foot below grade? Who gets to keep the wood?

A tree is a living thing and deserves good care. Be wise about the choice of your tree specialist.

For landscaping and gardening information, call University of Nevada Cooperative Extension at782-9960 in Douglas County. See the Web site at or ask garden questions at

n JoAnne Skelly is the Carson City-Storey County Extension Educator for the University of Nevada Cooperative Extension.