And can you confirm that this is zoysia? It has that dead zoysia look.

When did you plant and was it sod or seed?

And as Champ has mentioned, where do you live?

What is your watering schedule? How often and for how long do you water?

Thanks so much for weighing in. I'll post a closer picture tonight.

It's a mix of Perrenial Rye Grass and Fescue (JB Sun & Shade blend), and it was planted from seed. I live in Portland, OR.

The more I read on here, the more I suspect the problem was too much water...I'd been doing it on an almost daily basis for the first couple weeks--not terribly heavily-- then switched to every couple days (mostly in the evening, which I've since read is a mistake). But then we had a couple weeks of really hard rain. It was shortly thereafter that the damage set in.

If it is an issue of overwatering, will I need to till it and re-seed? Or is there something I can do to nurse it back to health? Is there something I should do to stop the spread of fungus (if that's the case)?

Thanks again!

And here are a couple close-up shots. Any help diagnosing the problem, or advice on what to do now, would be greatly appreciated.

That grass is dead. I'd reseed just the dead spots by simply dropping seed. Try not to water so much--the rest of the lawn looks good. Water only when you see signs of drought stress. Water the reseeded deadspots by manually.

Thanks, Mishmosh. Should I pull up the dead grass before I seed (sorry...longtime apartment dweller new to having a lawn)

i wouldn't. the seed will make its way to the soil on their own. good thing is, perennial ryegrass and fescue both germinate rapidly.