Mold

Mold is the catch-all term for the multiple fungal pathogens that attack cannabis throughout its lifecycle — most damaging during flowering when dense bud structure traps moisture and creates ideal infection conditions. The major cannabis molds: (1) Botrytis cinerea (bud rot, gray mold) — the most devastating, attacking bud interiors during late flowering, gray-brown fuzzy growth, see dedicated bud-rot entry; (2) Powdery mildew (Podosphaera, Erysiphe genera) — white powder coating on leaves and bud exteriors, looks like flour dusting, can spread across an entire grow within days; (3) Fusarium — root and stem rot causing wilting and brown discoloration at the soil line; (4) Pythium — root rot in hydroponic systems, especially in warm water above 70°F; (5) Aspergillus — opportunistic on harvested flower during improper drying/curing, produces dangerous aflatoxins; (6) Sooty mold — black coating on leaves, secondary infection following insect honeydew (aphids, whiteflies). General mold conditions: humidity above 60% RH, temperatures 60-75°F, poor airflow allowing stagnant moisture, dense plant structure trapping humidity, organic debris in growing area. Health risks: smoking moldy cannabis exposes the lungs to mycotoxins, fungal spores, and decomposition products causing immediate respiratory irritation and long-term risk of fungal pneumonia in immunocompromised individuals. Prevention strategies: humidity control (target 40-50% RH during flower), aggressive airflow with oscillating and inline fans, defoliation to expose bud sites, sanitation of grow space between cycles, beneficial microorganism applications (Bacillus subtilis, Trichoderma) that compete with pathogens, mold-resistant strain selection for high-humidity environments, and strict drying/curing protocols (60% RH, 60°F, 7-14 day dry period). Affected material must be discarded — mold cannot be safely treated or salvaged.