Black Root Rot Fungus May 2026

Pansy, Viola, Calibrachoa (Million Bells), Vinca, Petunia, Poinsettia, and Phlox.

Above-ground symptoms often mimic nutrient deficiencies, such as yellowing (chlorosis) and stunted growth, causing gardeners to over-fertilize, which only increases stress on the plant. The most distinct sign is a dramatic, firm, blackening of the roots—specifically caused by the buildup of dark chlamydospores. How the Fungus Spreads Black Root Rot - UC IPM black root rot fungus

The Silent Killer: Understanding and Managing Black Root Rot Calibrachoa (Million Bells)