This is a dchall question I think, hopefully he sees it.

If you abandon chemical, I would recommend Headway G. It is supposed to take care of almost all fungus, and has to active ingredients to help prevent resistance. There is one fungus I read about a long time ago (UF website I think) that can be confused with gray leaf spot and there is no fungicide for it. Treatment was to use a fertilizer with a specific ratio range - higher in potassium maybe, can't remember. If you use a fungicide your organic lawn may be back to square one since it will kill all those beneficial microbes...

Those weeks of rain you mention were the wettest since I moved to FL (JAX area) again a few years ago. No surprise we have fungus issues.

Thank you TS Garp. Hoping you escaped most of *sub* tropical storm Alberto in your area; Hurricane Irma didn't even do this last year. Before I got your response, I had to pick up the cornmeal (got coarse ground) so will attempt it... nothing to lose but time and money. Logic tells me to mow a tad lower, bag and toss the cuttings in my regular trash (not garden waste), and shoot for right before a "moderate" rainfall. I've also sent a message to my lawn angel to come work her magic, lol.

Meanwhile, I will try to track down that article you referenced. It's definitely spreading, whatever it is.