Identification

• Signs of powdery mildew include white or gray powder covering the surface of leaves, stems, flowers and fruit of diseased plants. Powdery mildew won't kill the plant, but it does cause yellowed leaves, dried, brown leaves and disfigured shoots. A severe infestation makes the plant unsightly.
  
  

Causes

• Overcrowding, high humidity and shading can cause powdery mildew fungi to develop on plants. The age, variety and condition of the plant also make it susceptible to the disease. Warm, dry climates also produce severe development of powdery mildew.
  
  

Prevention

• Inspect plants for the disease before purchasing. Plant the specimens in sunny, well-ventilated areas of the garden. Avoid over fertilizing the plants.
  
  

Organic Treatment

• Some organic treatments of powdery mildew fungi include baking soda spray and milk spray.