It is amazing that this simple natural ingredient will cure powdery mildew when chemical sprays were not as effective. It is great to hear that there is a natural cure, especially since the produce is grown to eat and drink. Organic gardeners such as me are thrilled! Basically, any kind of milk can be used, even skim milk. It is a green cure and inexpensive, how could that be any better!
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.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.

In his experiments with zucchini plants, Bettiol found that a weekly spray of milk at a concentration of at least 10% (1 part milk to 9 parts water) significantly reduced the severity of powdery mildew infection on the plants by 90%. While some gardeners may be tempted to increase the concentration of milk for more control, Bettiol found that once concentrations rose above 30%, an innoccuous fungus began to grow on the plants. How does milk control powdery mildew?

Hope that helps!