powdery mildew requires more than just spraying, or just pinching leaf off! Let me ask you this. How many plants do you have in your garden? It's important to understand how long the powdery mildew has been in your garden? I'll also say that once you visably see powdery mildew on you plants, it's been there at the very least one week! Now this stuff spreads, and spreads rather quickly especially if you are careless around it!? All tools that are used in your garden need to be sterilized too! Especially the ones used to eradicate the garden of powdery mildew!
I myself was hit by powdery mildew in Hawaii this year. Just two weeks ago I threw away roughly about 3/4 of a pound. Before thaata Today I will more than likely throw away all my dried "stash" too! Last night I noticed powdery mildew inside some bags on dried buds! So like I said earlier, today I will throw away the last of my stash too! In my case the powdery mildew was soooo extreme it required that I destroy everything in my garden!
Now before you go out and spend fist over dollar to battle this damn diease. Let's examine your home and see if you have some products at home to battle this problem?
In a pinch, look at your medicine cabinet for relief! Hydrogen Peroxcide works good! Just spray it on both top & bottom of infected leaf. Baking Soda with milk or water in a spray solution works too.
Products to use found at your local Garden supply store:
1. Zero Tolerance (Ed Rosenthal's own solution to this problem)
2. Greencure
3. Organicide
In closing, do not take "powdery Mildew', lightly because she will ruin your life if not dealt with ASAP. The last thing you wanna do is a "Sulfur Burn' to your entire garden area!
Good luck!