I'm seeing quite a bit of powdery mildew right now. I hate to just do blanket apps of fungicide to control this. At what point do you apply fungicide? On some lawns it has historically thinned the turf and I've had to reseed. I didn't have my applicators license until this year and now that I can do an application I will, if needed. I know that fungicide can damage good microorganisms as well as bad, so it seems like a last resort. I'd appreciate any help.