Powdery Mildew on Houseplants: Identification, Treatment, and Prevention

White powdery spots on leaves? Powdery mildew—a contagious fungal disease thriving in 70°F, low light, poor air circulation, and dry indoor conditions. Act fast to prevent spread.

Immediate Cultural Controls

• Don't mist; keep foliage dry when watering
• Space plants for airflow; add small fan
• Isolate infected plants immediately
• Remove and discard affected leaves

Common targets: begonia, African violet, kalanchoe, ivy, jade.

Home Remedy Sprays

Baking soda spray: 1 tbsp baking soda + ½ tsp liquid soap + 1 gallon water. Add 1 tbsp horticultural oil for adhesion. Spray top and bottom of leaves. Safe, non-toxic, works on some species.

Milk spray: 1 part organic milk (no hormones/preservatives) + 9 parts water. Spray weekly. Ventilate while drying to prevent mold.

Fungicides

If cultural/organic methods fail, use household fungicide per label. Apply outdoors to avoid indoor drift. Neem oil also effective.