Diagnosis
Diagnose: Boxwood Root Rot
Use these observations to decide what to check next.
Dark reduced feeder roots plus brown crown tissue in a wet-site pattern
Expose roots at the edge of the decline and compare them with roots from a nearby vigorous section. Firm, branching fine roots argue against advanced root rot; sparse dark roots that break easily, combined with brown tissue under the bark at the crown and a history of saturation, support a root or crown disease.
A diagnostic lab can determine whether Phytophthora is present.