Tree decline is often blamed on insects, diseases, or “mystery stress,” when the real cause lies below ground. This session provides arborists with a clear, repeatable framework for diagnosing subsurface issues, including compaction, fill layers, perched water tables, improper planting depth, poor soil structure, and legacy construction impacts.

Attendees will learn how to use simple field tools, soil color cues, infiltration tests, and crown indicators to quickly assess soil function without the need for a lab. We will walk through case studies that demonstrate how to connect aboveground symptoms (crown density, twig extension, taper, flare, and leaf size) to root-zone failures, and how to communicate these findings to clients in a way that justifies treatment recommendations.