How to Get a Connecticut Arborist License

Last updated: August 25, 2026

Connecticut licenses arborists, and the trigger is broader than doing the work — it is advertising, soliciting or contracting to do it. DEEP runs the license. The exam comes in three parts, including a tree identification section you must pass at 80% and a practical oral administered by the Connecticut Agricultural Experiment Station. It costs $200 to apply and $285 for the license — but that license runs five years, which makes it one of the cheaper credentials in the trade to hold once you have it.

What Connecticut Actually Requires

• An arborist license from DEEP if you advertise, solicit or contract to do arboriculture in Connecticut. Advertising alone is enough to need one.
• Work that counts as arboriculture: any work done for hire to improve the condition of fruit, shade or ornamental trees by feeding or fertilizing, or by pruning, trimming, bracing, treating cavities or other methods of improving tree conditions, or protecting trees from insects or diseases or curing those conditions by spraying or any other method.
• A written multiple-choice exam, passed at least three weeks before you sit the oral.
• A tree identification section passed at 80%.
• A practical oral exam at 70% overall, with a minimum of 7 out of 10 in at least seven of the ten categories — administered by the Connecticut Agricultural Experiment Station in New Haven.
• Demonstrated knowledge of pesticides — the statute requires knowledge of the proper methods of arboriculture and the dangers involved, plus the proper use and application of pesticides.
• No insurance requirement in the statute — Connecticut does not make cover a condition of the license.

What It Costs

Item	Cost	Notes
Application fee	$200	Explicitly not returnable — you pay it whether or not you pass
License fee	$285	For each license or renewal
License term	5 years	The commissioner may stagger expiry so one-fifth of licenses expire each year, and may prorate the fee for a shorter period
Pesticide certification	Included	The arborist license constitutes supervisory pesticide applicator status, category 3D
General liability insurance	Not required by statute	The risk is still entirely yours
Connecticut LLC	$120	Certificate of organization, including appointment of statutory agent

Coming From Another State

Can you transfer an out-of-state arborist license to Connecticut?

There is no published arborist reciprocity route in Connecticut. Plan on taking the exams.

That is worth stating flatly, because Connecticut does publish reciprocity for a neighboring credential: an applicant certified in another state under a law providing substantially similar qualifications, or examined by the Society of American Foresters, does not have to sit an examination for forester certification. No equivalent provision appears for arborists. If you hold an ISA certification or another state’s arborist license, it may help you prepare — it does not exempt you.

The reason sits in how Connecticut files the credential. The arborist license is category 3D under the commercial pesticide supervisor certification, administered by DEEP’s Pesticide Management Program rather than by a forestry board. You are entering the pesticide supervisory system, not a standalone arborist register — so the question to ask DEEP is about pesticide certification portability, not arborist reciprocity.

What the examination actually involves

Connecticut runs a two-stage exam, and the sequencing catches people who assume they can book both at once:

• Written exam — multiple choice, and it must be taken and passed a minimum of three weeks before your desired oral exam date. DEEP advises preferably more than a month. Failing costs a $200 retest fee.
• Oral exam — taken after the written, on a separate date, at The Connecticut Agricultural Experiment Station in New Haven. The first part is tree identification, which you must pass at 80% to continue to the practical the same day.
• Practical — ten questions, each from a different category. You need a total score of at least 70% and at least 7 out of 10 on at least seven of the ten categories. Both a decent average and consistency across categories, in other words.

The retake rule is the one to plan around. Fail the oral and you get one additional attempt before you have to go back and retake the written exam — which restarts the three-week clock and risks the $200 retest fee. If you are relocating for a job, build that possibility into your start date rather than assuming a single pass.

Before you assume anything about your own case, the Pesticide Management Program is the office that decides it: 860-424-3369 or deep.pesticideprogram@ct.gov. Ask specifically whether any part of your existing certification carries across, and get the answer before you move.

Advertising Is the Trigger — and the Tree ID Section Fails More People Than the Written

Start with the thing that surprises people: in Connecticut you need the license to advertise or solicit arboriculture work, not merely to perform it. Put a truck sign up, run an ad, or bid a job, and you are inside the licensing requirement before a saw comes out of the trailer. That is a genuinely different standard from states that regulate the act alone.

The exam is three separate hurdles, and they are not equally weighted in difficulty. The written multiple-choice paper is the gate — you must pass it at least three weeks before the oral, so the sequencing alone puts a month between starting and finishing. Then comes tree identification, which requires 80%, a higher bar than anything else in the process. Then the practical oral, at 70% overall with a minimum of 7 out of 10 in at least seven of the ten categories. The orals are run by the Connecticut Agricultural Experiment Station in New Haven.

The identification section is the one to respect. Most candidates come from the cutting side of the trade and can talk confidently about rigging, pruning cuts and hazard assessment; far fewer can name species reliably under exam conditions at an 80% standard. It is the most studiable part of the whole process and the most commonly underprepared.

The pesticide overlap is a real saving. The arborist license constitutes supervisory pesticide applicator status under commercial pesticide certification category 3D, and the statute requires you to show knowledge of the proper use and application of pesticides as part of qualifying. In most states these are two separate credentials with two separate fees and two separate renewal cycles. In Connecticut the arborist license does both jobs, which is a meaningful piece of the value for the $285.

On money, the five-year term changes the arithmetic. The headline is steep: $200 to apply, non-returnable, plus $285. But that license then runs five years, and the commissioner is empowered to stagger expiry dates so that one-fifth of licenses expire each year, prorating the fee where a shorter period is issued. Compare the annual states — Louisiana at $125 every year, Rhode Island at $25 every year — and Connecticut’s cost of holding the credential is modest. The cost is front-loaded into getting it.

What Connecticut does not do is make you insure yourself. The statute contains no insurance requirement. That puts Connecticut with Rhode Island rather than with New Jersey, which demands $1,000,000, or Maine, which sets $150,000 per occurrence and takes an affidavit. Nothing in the license process will prompt you to carry cover, and nobody will check. For a trade whose ordinary bad day involves a limb going through a roof, that silence is not reassurance.

How to Get Licensed, In Order

1. Stop advertising until you are licensed if you have not started — soliciting the work is itself inside the requirement.
2. Apply to DEEP with the $200 fee, knowing it is not returnable.
3. Sit the written multiple-choice exam, and pass it at least three weeks before you want the oral.
4. Drill tree identification to the 80% standard — it is the highest bar in the process and the one most people underprepare.
5. Take the practical oral at CAES in New Haven, targeting 7 out of 10 in at least seven of the ten categories.
6. Pay the $285 license fee and note your expiry — it may be less than five years if the commissioner staggered your date and prorated the fee.
7. Use your 3D supervisory pesticide status rather than paying for a separate applicator credential.
8. Arrange liability cover anyway, because Connecticut will never ask you for it.

Staying Licensed

A Connecticut arborist license runs five years and renews at $285. The commissioner may stagger expiration dates so that one-fifth of licenses expire each year, and may issue for a shorter period with the fee prorated accordingly — so do not assume your renewal falls exactly five years from the day you were licensed. Check the date on the license itself. Because the credential also carries supervisory pesticide applicator status in category 3D, letting the arborist license lapse takes that status with it. And since no insurance condition attaches to renewal, nothing in the five-year cycle will ever check whether your cover is still in force.

Frequently Asked Questions

Do I need a license to do tree work in Connecticut?

If you advertise, solicit or contract to do arboriculture, yes. Connecticut defines arboriculture as any work done for hire to improve the condition of fruit, shade or ornamental trees by feeding or fertilizing, or by pruning, trimming, bracing, treating cavities or other methods of improving tree conditions, or protecting trees from damage from insects or diseases or curing these conditions by spraying or any other method. Note that the trigger includes advertising and soliciting, not just doing the work.

How much does a Connecticut arborist license cost?

A $200 application fee, which is not returnable, plus $285 for each license or renewal. The license runs five years, so the ongoing cost works out lower per year than most states — Louisiana charges $125 every single year.

What is on the Connecticut arborist exam?

Three parts. A written multiple-choice exam, which must be passed at least three weeks before the oral. A tree identification section requiring 80% to pass. And a practical oral exam requiring 70% overall with a minimum of 7 out of 10 in at least seven of the ten categories. The Connecticut Agricultural Experiment Station in New Haven administers the oral exams.

Does a Connecticut arborist license cover pesticide use?

Yes — the arborist license constitutes supervisory pesticide applicator status under commercial pesticide certification category 3D. The statute requires applicants to show knowledge concerning the proper use and application of pesticides alongside knowledge of arboriculture and the dangers involved.

Tree work sits alongside our full guide to starting a landscaping business in Connecticut, and the wider guide to starting a business in Connecticut. Or see how every state handles tree work in our arborist license requirements by state guide.

Can you transfer an out-of-state arborist license to Connecticut?

No published reciprocity route exists for arborists. Connecticut does provide reciprocity for forester certification, where an applicant certified in another state under substantially similar requirements or examined by the Society of American Foresters can skip the exam, but no equivalent provision is published for arborists. The Connecticut arborist license is category 3D under the commercial pesticide supervisor certification, so portability questions go to DEEP’s Pesticide Management Program on 860-424-3369.

Sources

Source	What It Covers
CT DEEP — Commercial Arborist License	The advertising, soliciting and contracting trigger, the statutory definition of arboriculture, the three-part exam with the 80% tree identification and 70% oral standards, CAES as administrator, and the category 3D supervisory pesticide applicator status
Connecticut General Statutes Chapter 451, Sec. 23-61b	The $200 non-returnable application fee, the $285 license or renewal fee, the five-year term with staggered expiry and prorating, and the examination standard — and the absence of any insurance requirement
CT.gov Business — domestic LLC forms and fees	The $120 certificate of organization fee
Connecticut DEEP — Commercial Arborist License	The arborist license as pesticide category 3D, the written and oral examination sequence, scoring thresholds and retake rules
Connecticut DEEP — Arborist Program	Program contact details and the licensing requirement for arboriculture in Connecticut