Appraise a tree or landscape plant using the CTLA Guide for Plant Appraisal

Steps

1. Use the CTLA Guide for Plant Appraisal, 10th Edition (published 2019, jointly with ISA), as the governing methodology — confirm no newer edition has superseded it before citing an edition number in a formal appraisal.
2. Select the appropriate appraisal approach for the situation: Cost Approach, Income Approach, or Sales Comparison Approach, as defined in the Guide.
3. Within the Cost Approach, choose the applicable technique — Trunk Formula Technique for large landscape trees (extrapolating from the largest commonly available nursery stock), Direct Cost, or Cost Compounding — matched to tree size and available comparable data.
4. Document species, condition, location, and functional factors used in the valuation using the Guide's structured worksheets, since these drive the final adjusted value.
5. Reference the Guide explicitly in the appraisal report to support defensibility in insurance claims, litigation, or municipal tree-removal-penalty disputes.