Do you need a certified arborist, or a good crew?
Updated 2026-09-04
Best overall
ISA Certified Arborist
For diagnosis, risk and anything that will be read by an insurer or a planning department.
Best for straightforward work
A good insured crew
Deadwood removal, clearance pruning and a clean removal need skill and insurance, not a credential.
Best value
Arborist to specify, crew to execute
Pay for the judgement once, then have the work done by whoever is competent and insured.
Our pick: ISA Certified Arborist
| Criterion | Tree trimmer / climber | ISA Certified Arborist |
|---|---|---|
| Climbs and prunes | Yes | Yes |
| Written exam and CEU renewal | No | Yes |
| Diagnoses disease and decline | Sometimes, informally | Trained to |
| Writes a report an insurer will read | No | Yes |
| Supports a permit or hazard exemption | No | Usually yes |
| Publicly verifiable | No | Yes — ISA directory |
| Carries insurance | Must be checked separately | Must be checked separately |
When the credential earns its money
Four situations, and they all end in a document: an insurance claim about a tree that failed; a permit application or a hazard exemption; a dispute with a neighbour or a developer; and a diagnosis where the choice is treat or remove — as with oak wilt or emerald ash borer.
Everywhere else, what you actually need is a competent, insured crew who show up when they say they will. Verify insurance in both cases — the certificate, direct from the insurer.
Verifying the claim
Certification attaches to a person, not a company. "ISA certified company" is not a thing; ask which named individual holds it and for their certification number, then check them in ISA's public directory. It takes about a minute and it is the whole of the check — details in the credential guide.
Watch
What it costs, roughly
Federal data gives the shape: the hourly median for tree trimmers and pruners is $24.50 and the ninetieth percentile $38.61 (BLS OEWS, May 2025). Consulting and report work sits in that upper band, which is why an assessment visit is priced like professional advice rather than like an hour of pruning — and why doing your own first pass before you call is worth the ten minutes.