Arborists give sound advice on tree care and perform tasks professionally. However, all arborists are not the same, and there is an even wider difference between arborists and uncertified tree-care workers. Choose carefully. The health of your landscape is at risk.
To become a Certified Arborist, a tree-care professional must pass a grueling test covering basic knowledge of biology, nutrition, fertilization, tree/soil relations, water management, identification, selection, installation, pruning, diagnosis, construction, climbing, cabling, bracing and safety. Arborists maintain certification by attending training programs to keep up to date. Certification is no guarantee, but it is a step in the right direction.
Research on tree care constantly yields new techniques and products that are better for trees and the environment. An arborist must keep up with improving techniques.
If appropriate, ask to see current certificates of liability and workers' compensation. Take a look at their equipment. A dirty or wet climbing rope should flash a warning. Safety is paramount. Are they prepared for emergencies?
Some arborists send employees to conferences. Some encourage employees to become certified as an arborist or tree worker.
It is well known that topping damages trees. If a tree-care professional advertises topping and is willing to do that to your healthy tree, take that as a warning.
A professional would not use spurs to climb a healthy tree. Spurs wound the tree and often carry diseases from trees previously taken down.
Urban trees are frequently living with infections from old wounds. An arborist can monitor insect and disease problems and prescribe practices that can help the tree defend itself. He or she can advise you if you plan physical changes to the environment that will affect the trees and their root systems.
A signed contract requiring work be completed according to American National Standards Institute A300 Standards is advisable. The ANSI defines techniques for pruning, fertilization, safety, and other categories of tree care. Your arborist should have a copy of the standards.
Hire people who have the knowledge, experience, and equipment to protect your property. Many reputable companies can invoice their work in stages or on completion and accept payment on receipt of the invoice or within two weeks.
Ask for recommendations, but consider the credibility of your sources. Get bids on a project, but do not sacrifice long-range health of your trees to save a few dollars.