Black Root Rot Fungus Apr 2026

Hollies (especially Ilex crenata ), Boxwood, and Citrus. Crops: Tobacco, Cotton, Carrots, and Lettuce.

Black root rot thrives in cool, wet, and often alkaline (higher pH) soil conditions. It is a versatile pathogen, affecting a wide range of plants, including: black root rot fungus

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 Hollies (especially Ilex crenata ), Boxwood, and Citrus

In the quiet world of nursery production and home gardening, few pathogens are as persistent—or as devastating—as ( Berkeleyomyces basicola , formerly Thielaviopsis basicola ). This soil-borne fungus operates in the shadows, attacking the plant's foundation and turning healthy, white root systems into decayed, blackened messes, leading to stunted, wilted, or dead plants. The Anatomy of an Infestation It is a versatile pathogen, affecting a wide

The Silent Killer: Understanding and Managing Black Root Rot

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