10 Questions to Ask Before Hiring an Arborist

Hiring someone to work on your trees is a bigger decision than most people realize. Trees are valuable assets, both financially and ecologically, and the wrong person with the wrong tools can cause damage that takes decades to undo. Whether you need pruning, removal, or just an assessment, here are the ten questions that will help you separate the professionals from the pretenders.

1. Are You Insured?

This is the most important question on the list, and it should be the first thing you ask. A tree company working on your property should carry commercial general liability insurance (minimum $2 million) and Workers' Compensation Board (WCB) coverage for their employees.

Why it matters: If an uninsured crew damages your property or an uninsured worker is injured in your yard, you could be held financially responsible. Ask for a certificate of insurance and verify it is current. Any legitimate company will provide this without hesitation.

2. Do You Have ISA-Certified Arborists on Staff?

The International Society of Arboriculture (ISA) certification is the industry standard for arborist competency. It requires passing a comprehensive exam and ongoing education. Not every crew member needs to be certified, but at least one person involved in your job, ideally the person making decisions about what to cut, should hold this credential.

You can verify certification at the ISA's online directory.

3. Can I Get a Written Quote?

A professional tree company provides written quotes that clearly describe the work to be done, specify which trees are included, state the total price, and outline what is and is not included (cleanup, disposal, stump grinding). Verbal quotes and vague descriptions are red flags.

A good quote should be specific enough that if a dispute arises, both parties can point to the document and agree on what was promised.

4. What Is Included in the Price?

This is where many homeowners get surprised. Ask specifically about:

• Cleanup of all debris from the yard
• Hauling and disposal of wood and brush
• Stump grinding (often quoted separately)
• Removal of wood rounds or logs (some companies leave firewood-length pieces for the homeowner)
• Any potential additional charges for complications

5. Do You Hold a City of Calgary Business Licence?

The City of Calgary requires businesses operating within city limits to hold a valid business licence. This is a basic indicator of legitimacy. You can verify a company's business licence through the City's online registry. An unlicensed operator is cutting corners before they even pick up a chainsaw.

6. How Will You Prune This Tree?

This question separates the knowledgeable from the uninformed. A good arborist will explain their approach in terms you can understand: which branches they plan to remove and why, what percentage of the canopy they expect to take, and what pruning standards they follow. Listen for terms like "crown cleaning," "crown thinning," and "structural pruning." These are standard arboricultural practices.

Red flag answers include "we will take it down to size," "we will top it back," or any vague description that does not address the specific condition of your tree.

7. Will You Use Climbing Spikes on My Trees?

Climbing spikes are metal points attached to the climber's boots that puncture the bark with every step. They are appropriate for tree removal, where the tree is coming down anyway. They should never be used on a tree that is being pruned and will continue to grow. Each spike wound damages the cambium layer and creates an entry point for disease and decay.

If a company uses spikes on pruning jobs, they either do not know the standard or do not care. Either way, look elsewhere.

8. What Happens if Something Goes Wrong?

Accidents happen in tree work. A branch bounces unexpectedly and dents a fence. A section of trunk swings into a gutter. The question is not whether something could go wrong but whether the company is prepared for it. A reputable company will have a clear answer: "Our insurance covers property damage, and we take responsibility for fixing it."

If the answer is vague or dismissive, that tells you everything you need to know about how they will handle a problem.

9. Can You Provide References or Reviews?

Online reviews on Google, Facebook, or other platforms give you a window into how the company performs on real jobs. Look for reviews that mention specific details about the work quality, communication, cleanup, and professionalism. A company with dozens of detailed, positive reviews has earned them through consistent performance.

Be cautious about companies with no online presence, only a handful of reviews, or reviews that seem generic or fake.

10. When Can You Start, and How Long Will It Take?

This is a practical question, but the answer can be revealing. If a company says they can start tomorrow during peak spring season, they might not be very busy, which could be a red flag. A reputable company during busy season will typically have a wait time of one to four weeks. They should be able to give you a realistic scheduling window and an estimate of how long the job will take.

For emergency work (a tree on your house, a hanging limb over a walkway), most good companies offer expedited service, often within 24 hours.

Bonus: Questions You Should NOT Have to Ask

A good tree company will proactively address these things without being asked:

• They will mention their insurance and offer to provide a certificate
• They will explain the work they recommend and why
• They will point out things they notice during the estimate, even if it is not what you called about
• They will tell you if a tree does not actually need work (yes, honest companies do this)
• They will provide a clear, written quote before starting any work

The right arborist will not be annoyed by your questions. They will welcome them. A company that is proud of their work, their crew, and their standards will be happy to talk about all of it. The ones who get defensive or evasive are the ones you should avoid.