Is every tree service company also a certified arborist?

No. Many tree services don't have one on staff. ISA certification is a specific credential that requires passing an exam and ongoing continuing education. Ask before you book.

Why does it matter if I'm just trimming a tree?

Wrong cuts on the wrong tree shorten its life and can create future structural hazards. A certified arborist determines what should and shouldn't be cut — and where the cut goes.

Do I need an arborist for stump grinding?

Not usually. Stump grinding is a service-execution job, not a decision-heavy one. The tree is already down.

How do I verify someone is ISA-certified?

Ask for their certification number, then look it up on the ISA's public Find an Arborist directory. The credential is verifiable in under a minute. If someone pushes back on that question, take that as your answer.

What's the difference between ISA certification and TCIA accreditation?

ISA certifies individuals. TCIA accredits companies — covering safety practices, insurance, training, and business standards across the whole operation. They're complementary, not interchangeable.

What does a tree health evaluation actually include?

A walk of the tree with a certified arborist: canopy condition, structural assessment, root flare and root collar, signs of decay or disease, and what's around it that changes the risk picture. You get a written read with recommendations — keep, monitor, prune, or remove.

Resource

Certified Arborist vs. Tree Service: What Do You Need?

An arborist tells you what the tree needs. A tree service does the work. The right job has both.

By Tree Giants · Reviewed and updated May 30, 2026

Quick answer

When should I ask for certified arborist support?

Ask for a certified arborist whenever the decision matters more than the cut. Tree health questions, removal recommendations on a tree that might be saveable, risk evaluations on a mature tree near a structure, anything that needs a second opinion before you commit to expensive or irreversible work.

A tree service handles execution: rigging, climbing, cutting, hauling, grinding. Tree Giants has an ISA-certified arborist on staff — so you get the judgment and the work from the same team.

Tree health questions

Decline, disease, pest pressure, internal decay — these are diagnosis questions, not cutting questions. A certified arborist knows what to look for and what the findings mean. A tree crew knows how to get a limb down safely. Those are different skill sets.

Removal recommendations

If a company says "this tree has to come down," a certified arborist can confirm — or push back. Some trees that look gone aren't. Some that look fine are failing. The ISA credential matters when the recommendation is expensive, irreversible, and based on what someone saw in five minutes.

Pruning and trimming decisions

Pruning is more than removing limbs. It's choosing which limbs come off, where the cut lands relative to the branch collar, and what the crown looks like when the work is done. A certified arborist directs that decision — especially on mature or high-value trees where a bad cut does lasting damage.

Risk evaluations

For trees near a house, over a play area, or close to where people regularly gather, a structured risk evaluation from a qualified arborist is worth the time and the fee. Our tree health evaluations page covers what that process includes.

Tree service execution

Once the decision is made, you need a crew that can climb, rig, cut, and clean up safely — and that leaves the yard in better shape than they found it. That's the service side. The two work best when they come from the same operation.

What Tree Giants brings

ISA-certified arborist on staff. Full-service crew for the cut, cleanup, and stump grinding. One call, one team, one person walking the property with you before any work begins. No payment due until the job is complete.

Questions to ask before you book any tree company

Do you have an ISA-certified arborist on staff? What's their certification number?
Do you carry workers' comp and general liability? Can I see a current certificate?
Will the arborist actually be on the property, or only available by phone?
Who decides which cuts get made — the arborist, or the crew lead in the moment?
What's your written scope and pricing process? When is payment due?

A company that handles all five questions cleanly is usually the one you want. The companies that get evasive on insurance, certification, or written scope are the companies that show up in cleanup-call conversations later.

When a tree service alone is enough

Storm cleanup with no decisions to make, hauling a tree that's already down, grinding stumps from a prior removal, brush clearing on a clean lot — these are execution jobs. A capable crew with the right equipment handles them. You don't need an arborist signing off on what's already been decided.

When the arborist's read is what you're paying for

Mature trees near a house. Trees that look like they might be saveable. Trees that look fine but show any of the warning signs in our dangerous tree guide. Tree health evaluations for insurance documentation, real estate transactions, or a property dispute. In all of these, the value is in the assessment, not the cutting — and the assessment should come from someone qualified to make it.

Why having both under one roof matters

When the arborist and the crew are different companies, the communication gaps show up in the work. The arborist marks limbs the crew interprets differently. The scope gets renegotiated mid-job. The homeowner ends up translating between two parties. When it's one operation — assessment, scope, crew, cleanup — the work matches the plan.