A “risk tree” is a tree with structural defects likely to cause failure of all or part of the tree, which could strike a “target.” A target can be a vehicle, building, or a place where people gather such as a park bench, picnic table, street, or backyard. Because of the natural variability of trees, the severity of their defects, and the different sites upon which they grow, evaluating trees for hazardous defects can be a complex process. Inspecting trees for potential hazard liability is one of the most important components of any tree management system.

Prioritizing risk hazards, budgeting for their removal and developing a timetable for action is critical to protect the safety of those who live, work or relax near trees. Many tools are available for assessing potential hazard trees and managing their removal from the landscape