Tomatoes Won't Ripen: Heat, Heavy Fruit Load, and Solutions

Two causes: (1) Heavy fruit load—leaves can't supply enough sugar/hormones. (2) Heat >85°F stops carotene/lycopene production. Roots need <80°F, fruit needs leaf shade. Pick at 1/3 pink (breaker stage), ripen indoors. Ideal temps: 70–75°F day, 60–65°F night. Above 85°F causes flavor/texture/color loss. Below 50°F causes chilling injury (2–3 day recovery).