By Enrique Arayata
ISA Certified Arborist® OH-7252A
February 27, 2025
Have you ever wondered how to become an ISA Certified Arborist®? To first answer this question, it’s probably good to know what an arborist is and what the acronym ISA means. An arborist is a professional who practices arboriculture and the study, management, and cultivation of trees, shrubs, and other woody plants. ISA is the International Society of Arboriculture, a non-profit organization that serves the tree care industry by promoting the professional, proper practice of arboriculture, developing arborists’ skills and expertise, and educating the public about trees, their benefits, and how to properly care for them. ISA offers multiple credentials, one of which is the ISA Certified Arborist® credential. ISA certifies that these arborists have a minimum of 3 years’ full-time experience in tree care and that they have passed the 200-question arboriculture exam focusing on 10 different categories of trees and tree work. Obtaining the ISA Certified Arborist® credential is a strong indication that an arborist is dedicated, knowledgeable, experienced, and caring when it comes to trees. To become an ISA Certified Arborist®, there are 5 general steps!
1. DEVELOP AN INTEREST IN ARBORICULTURE
Planting trees at our office!
The first step to becoming an ISA Certified Arborist® is to develop an interest in arboriculture such as tree species, tree identification, growing habits, tree structure, planting sites, diseases, pests, soil science, tree planting, tree preservation strategies, tree removal techniques, plant healthcare, working with trees around construction, tree risk assessment, safe practices, urban forestry, and so much more!
2. HAVE 3 YEARS OF FULL-TIME ARBORICULTURAL EXPERIENCE
ISA requires that testing candidates have a minimum of 3 full-time years of arboricultural work experience, formal education, or a combination of both. One example could be finishing your junior year of college at a university majoring in forestry or horticulture. Another example could be working for a tree care company for 3 years as a ground worker, climber, crew leader, plant healthcare technician, or sales manager. Other rapid-fire examples of practical arboricultural experience could be working at a nursery, landscape company, municipality, state forestry agency, utility company, an academic arboriculture department or extension program, a tree consultancy, or pest control provider. Regardless, documentation of experience with related references is required for verification.
3. STUDY FOR THE EXAM
A very common guide that people use when studying for their ISA certification!
Now it’s time to study for the ISA Certified Arborist® Exam! Even though ISA requires applicants to have a minimum of 3 years of full-time arboriculture experience/education, you can study in the meantime so that you’re ready to take the exam as soon as you have 3 years under your belt. In terms of what to study, ISA recommends the 4th Edition Arborists’ Certification Study Guide. This is what I and almost everyone at Russell Tree Experts used. ISA has a practice exam on their website set up in the exact same fashion as the actual exam. There are also free resources online such as lessons on YouTube, Quizlet flashcards, and sample questions online. On Facebook, there are various groups pertaining to the ISA Certified Arborist® exam where you can ask questions, study together, and learn from one another! One other resource is the Certified Arborist Review sessions at the Ohio Tree Care Conference. There is an approximate 1-hour session for each of the 16 chapters in the study guide led by different ISA Certified Arborists® that I found incredibly beneficial!
Duration of study is different for everyone. I know coworkers who read the book in less than a month and passed the test on the first try, but I also know coworkers who periodically studied over the course of 3 years and then passed the test as soon as they were eligible to apply. Personally, I studied approximately 1 page per day throughout 2024 since the study guide is 369 pages long, reviewed all of January 2025, and then took the test in February!
4. APPLY FOR AND SCHEDULE THE EXAM
Once you are eligible and feel confident in your studies, it’s now time to apply for and schedule the ISA Certified Arborist® exam! First, you’ll want to visit ISA’s website, create an account, and then become a member of your local chapter. Central Ohio’s local chapter is Ohio Chapter ISA. Afterwards, apply for testing eligibility. This is when ISA will ask for documentation of 3 years’ work or educational experience in arboriculture. Once you’re approved, you can schedule your exam.
Ohio Chapter ISA: Ohio’s local ISA chapter.
For the exam, you can choose between a computer-based exam or a paper-based exam. Both require you to drive to a proctored exam site. Both exams are in the same format, cover the same topics, and are at the same difficulty level. Advantages of the computer-based exam is that there are more testing sites, potentially resulting in a shorter drive in most cases, being able to know your results immediately compared to waiting up to 6 weeks to know the results of a paper-based exam, and to save time clicking your answer as opposed to filling in 200 bubbles on a scantron with the paper-based exam. Two potential downsides of a computer-based exam are that it is costlier than the paper-based exam due to a $125 administrative fee and it is a little more tedious to click back-and-forth between questions compared to flipping the physical exam book pages. Advantages of the paper-based exam are if the testing site is closer to you than the computer-based exam testing site, being able to physically flip back-and-forth more quickly between questions, and having something physical and not digital to look at for 3.5 hours in case eye strain is a concern.
Regardless of which exam you choose, you will need to select the specific testing date and location, submit an application to take the test, and then receive approval before you are officially enrolled. At the time of writing this ARBOR ED™ article, the exam fee ranges from $170 to $405 depending on your membership status and which testing option you choose.
5. TAKE THE EXAM
Now it’s time to take the exam! The ISA Certified Arborist® exam comprises of 200 multiple-choice questions. Each question has 4 possible answers. There are no “all of the above” answer options, no multiple correct answers, and no images throughout the entire exam. There are 3.5 hours allotted to complete the exam. In order to pass, a 76% or higher is required. The exam content material is divided into 10 domains of knowledge:
Tree Biology (11%)
Identification and Selection (9%)
Soil Management (7%)
Installation and Establishment (9%)
Pruning (14%)
Diagnosis and Treatment (9%)
Trees and Construction (9%)
Tree Risk (11%)
Safe Work Practices (15%)
Urban Forestry (6%)
From personal experience and chatting with multiple coworkers, 3.5 hours is plenty of time to take the exam. One tip is that some questions can provide context clues that can help answer a different question in the exam, so do not feel discouraged to skip a question and come back to it later. There should be at least 30 to 60 additional minutes to revisit unanswered questions or review unsure questions.
MAINTAINING YOUR ISA CERTIFIED ARBORIST® CREDENTIAL
Some of our fellow climbing ISA Certified Arborists® in a tree!
Once you’ve passed your exam, congratulations! You’re officially an ISA Certified Arborist®! Your certification is valid for 3 years. To maintain your certification, you can either retake the exam again OR you can earn 30 Continuing Education Credits (CEUs) before your certification expires. CEUs can be earned through opportunities such as safety trainings or meetings, podcasts and quizzes, e-learning modules, webinars, workshops, and/or conferences. The number of CEUs will vary depending on the length of opportunity and level of depth. For more information, check out isa-arbor.com.
In 2022, ISA reported 35,944 ISA Certified Arborists® and 991 ISA Board Certified Master Arborists® worldwide. Russell Tree Experts is proud to have over 20+ ISA Certified Arborists® on staff, 3 of which are ISA Board Certified Master Arborists®. To request a free tree quote, give our local office staff a call at (614) 895-7000 or visit RussellTreeExperts.com/Quote!
ADDITIONAL ARBOR ED ARTICLES!
Enrique Arayata I Media Production Manager, Russell Tree Experts
Enrique is an ISA Certified Arborist® and FAA Certified Remote Pilot. In his free time, he enjoys working out, hanging out with his family and girlfriend, video production, photography, cars, technology, and cooking. Enrique has a BA in moving image production with a double minor in film studies and studio art specializing in photography from The Ohio State University, and an AA in web graphic design from DeVry University. His favorite tree is the Kwanzan cherry tree.