Powdery Mildew on Indoor Rosemary: Edible-Safe Treatment

Powdery Mildew on Indoor Rosemary: Edible-Safe Treatment

Indoor rosemary with heavy powdery mildew in window box with thyme, oregano, cinnamon basil: need edible-safe control.

Cornell Formula (Safe for Herbs)

• 1 tbsp baking soda + 1 tbsp cooking oil in 1 gallon water.
• Scale down for spray bottle.
• Spray every 3–4 days with fresh mix.

Benefits

• Slows mildew; allows healthy new growth.
• Does not eliminate fungus permanently.
• Mildew-affected leaves edible (fungus harmless to humans).

Prevention

• Improve air circulation.
• Water at soil level.
• Remove severely affected leaves.

Consistent spraying yields usable herbs despite mildew pressure.