If anything, it looks--from a distance and off the cuff--like a minor spotty disease that's not doing much damage and doesn't have any inclination to do anything nasty.

I might be inclined to throw some Milorganite on it, irrigate normally (if it doesn't rain), and keep an eye on it. Ten to one it'll just go away on its own.

Now if it's been steadily spreading and there are lesions on the leaves and it's getting worse...we'd need to know that. :-)

Hi, thank you very much for you comments. There are no lesions which is why I convinced it was fungus. But it was very hot the last few weeks and have at times watered daily, so that may have done it. I'll water 2-3 times a week and hopefully it just clears up :)

Cut that water back to once a week and call it a done deal...particularly if it's a fungus. :-)

Sometimes grass next to concrete gets overheated, even with watering due to the extra heat thrown off by the paving.