Powdery mildew on grass!!

Sheesh it's not even the middle of May yet!  Powdery mildew in multiple places on the yard grass.  Mostly along edges, perhaps gets less air flow there.   I haven't mowed yet and the grass has grown quite long, maybe could have avoided this with more pro-active mowing.  Scissored the edges and tossed whatever powdery mildew I could.  Then whipper snipped the rest.