Natural Fungicides

• Liquid sulfur and liquid copper fungicides are available for purchase at most garden supply stores. They kill and prevent powdery mildew on plant leaves. You can create your own natural fungicide at home by combing equal parts milk and water, or adding 5 teaspoons each of baking soda and hydrogen peroxide to a gallon of water.
  
  

Applications

• As a preventative, liquid sulfur or copper can be applied to plants before the rainy season begins. Once powdery mildew has appeared, spray the infected leaves with the natural fungicide, focusing your attention on the upper surfaces of the leaves.
  
  

Considerations

• You will need to apply natural fungicides to plants infected with powdery mildew every five days or so to keep the mildew under control. Removing dead or infected leaves, and watering plants at the roots rather than from overhead, will help stop the mildew from spreading.