ISA-CA Exam Domains 2026: Complete Guide to All 7 Content Areas
Understanding the ISA-CA exam domains is the foundation of effective exam preparation.
ISA-CA Domain Deep Dives
Domain Deep Dives for the ISA Certified Arborist (ISA-CA) exam - 8 in-depth guides to help you prepare with confidence. Browse all study resources or jump straight into a guide below.
ISA-CA Domain 1: Tree Biology (7%) - Complete Study Guide 2027
Tree Biology represents 7% of the ISA Certified Arborist exam, translating to approximately 12-14 questions out of the 175 scored items.
ISA-CA Domain 2: Soil Science (6%) - Complete Study Guide 2027
Domain 2 of the ISA Certified Arborist exam focuses on soil science, representing 6% of the total exam content.
ISA-CA Domain 3: Water Management (5%) - Complete Study Guide 2027
Water management represents 5% of the ISA Certified Arborist exam, translating to approximately 9-10 questions out of 175 scored items.
ISA-CA Domain 4: Tree Nutrition and Fertilization (5%) - Complete Study Guide 2027
Domain 4 of the ISA-CA exam focuses on Tree Nutrition and Fertilization, comprising 5% of the total exam content.
ISA-CA Domain 5: Tree Selection and Installation (8%) - Complete Study Guide 2027
Domain 5 of the ISA Certified Arborist exam focuses on the critical skills needed to select appropriate trees for specific sites and install them...
ISA-CA Domain 6: Pruning (12%) - Complete Study Guide 2027
Pruning represents one of the most critical and frequently tested domains on the ISA Certified Arborist exam, comprising 12% of the total exam content.
ISA-CA Domain 7: Diagnosis and Treatment (14%) - Complete Study Guide 2027
Domain 7: Diagnosis and Treatment represents the largest single content area on the ISA Certified Arborist exam, accounting for 14% of all questions.
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