Ranunculus Powdery Mildew: Identification and Organic Control

Ranunculus Disease

Potted ranunculus in Chandigarh (15–22 °C) shows wilting, yellowing, and a wipeable whitish coating on leaves. No mites found.

Diagnosis: Powdery Mildew

The "dewy" coating is classic Podosphaera powdery mildew—common in cool, humid conditions with poor air flow.

Treatment Options

1. Lightweight horticultural oil (not cooking oil): Spray to runoff. Mildew flakes off as it dries.
2. Neem oil: Native to India, widely available. Controls mildew, mites, and insects. Spray weekly until clean.

Flowers hit by spray may abort, but the plant will rebloom.

Prevention

• Space pots for air circulation.
• Water at soil level—keep foliage dry.
• Empty saucers promptly.
• Reduce humidity around plants.