A disease (usually fungal, sometimes bacterial) where soil pathogens attack and decay plant roots, causing wilting, yellowing, and plant death despite moist soil.
Root rot happens when roots stay waterlogged too long. Soil fungi or bacteria colonize weakened roots, causing decay. The plant can't absorb water or nutrients despite soil being wet (roots are dead). Symptoms: wilting despite wet soil, yellowing leaves, overall plant decline. It's preventable with good drainage; once established, it's hard to cure—sometimes requiring removal of the plant.
Root rot is a silent killer. Understanding that wet soil can cause wilting (not drought) helps diagnose and prevent it.