Powdery mildew. You've probably had it plague one of your plants at some point or another during your years of gardening.
Powdery mildew is one of the most widespread and easily identifiable plant fungal diseases. From vegetable gardens to rose gardens, ornamental trees and shrubs, almost no type of plant is immune.
You’ve probably seen it many times. White or gray powdery spots appear, most of the time covering the entire leaf surface. It’s also found on plant stems, flowers and even fruit. Fortunately, the symptoms of powdery mildew are usually worse than the actual damage. Rarely is it fatal to the plant. Advanced stages can cause plant foliage to yellow, curl or turn brown and eventually cause the plant to stop producing leaves or flowers. Most of the time, it's just an unsightly nuisance.
Conditions that favor mildew formation include dry foliage, high humidity, low light and moderate temperatures. Here's some things you can do to help curb powdery mildew from ruining your plants.
*Make sure your plants have good air circulation around them
*Place plants where they will get 6+ hours of sunlight each day
*Grow disease resistant varieties
*Avoid over fertilization. New growth is more susceptible. Try using slow release fertilizers.
Baking Soda (sodium bicarbonate), is possibly the best known of the home-made, organic solutions for powdery mildew. Most effective when applied in the early stages or before an outbreak occurs.
There's no CURE for Powdery Mildew, but you can control it. Try adding a tsp. or so to a spray bottle and add water. When the weather is dry, spray your water and baking soda mixture onto the leaves that are affected. Repeat when it rains. The ph level will create an unsuitable environment for the mildew spores to reproduce and spread.