Also, I removed two 1 SF areas of turf to check for grubs. Found 1 grub in 2 SF.

There's one more test you can do for bugs. Put a piece of paper on the grass and wipe your hand through the grass away from the paper. That movement will flick any loose insects onto the paper. You're looking for chinch bugs. I suspect you don't have them, but if you do the treatment is completely different. If you have chinch bugs you can either apply beneficial nematodes (if you want to remain organic) or spray with a chemical insecticide.

If you don't have chinch bugs then this is almost certainly a disease. The rains we've had since last October piled it on leaving many of us with diseased lawns by June. Cracked corn was correct; however, you should be able to find corn meal fairly easily at a feed store. I get it either at Ful-O-Pep stores or Mumme's feed store. Both are milled along Hwy 90 so they're local and available. Deer will smell the corn but they'll have a harder time getting any appreciable amount. Besides you're going to wet it down so it's sort of melted onto the soil surface. Just water enough to wash the corn dust off the grass and down onto the soil. No need to saturate the soil, although if you were doing a normal watering of 1 inch, that would be fine.

You need to bite the bullet and mow it lower. You have to mow it at your mower's lowest setting and bring it up one notch to get it down where it needs to be. Bermuda grows off of stems. When you mow it off from 2.5 inches to 2, the stems are 2 inches tall. When you mow it down to 1 inch, the stems will be 1 inch tall. When the grass blades come out of the stems, they will grow up from the top of the stem. If you can mow down to 1/2 inch and mow it 3x per week, the stems will start to grow horizontally in a survival response to the assault on the upright stems. Then the blades come out of the stems all along the way increasing the density considerably. Check out this thread for pictures of what it looks like.

Thank you, dchall, for your advice (and information on countless threads here).

I didn't find any chinch bugs, so I'll try to source corn meal in the area (it isn't carried by my local feed store). Should I hold off on applying milorganite in the meantime?

Regarding mow height, should I wait for temperatures for come down a bit before reducing height? Should it be done all on one day?

Thank you also for the above link - if I lower the mower below 1", I'll need the leveling techniques!

A nearby small town feed store is trying to source corn meal, then I'll try Callahans and Georgetown. In a pinch, I guess I could use cracked corn (which I can get) and top it with milorganite to keep the deer at bay. Again, thanks. I hope to have updated pictures of a lower and greener lawn in a couple months!

For anyone in the greater north Austin area looking for corn meal, it's available at Georgetown Farm Supply on SH 29 near IH 35.

That's good information, thanks. Looking forward to the pix in a month.

I'm in Round Rock for a class this week. I might swing by that feed store and look around. My daughter is at Southwestern, so I'm up here sort of frequently.

Two months later, I'm mowing the lawn at 1" and absolutely love the height of cut (as do my kids). Areas that were previously thriving have recovered well from the scalping, have further thickened, and look great. Areas that were brown have recovered much more slowly.

After numerous armadillo "aerations", I'm not convinced my problem wasn't grubs. While I've yet to find large populations, the diggings and type of deterioration points towards some infestation. Since my last post, I've spread corn meal, half rates of milorganite, and most recently, alfalfa. I've also shampooed areas that seemed most affected by poor growth or recovery. I have had to cut back somewhat on irrigation, but worst areas are being watered with a manual sprinkler. One month ago, I applied light grub control (grub-ex, I believe) in two areas that were routinely hit by armadillos (as confirmed by trail camera). They've not been asactive in those areas since application.

The following photos were taken this evening after mowing, but the overall image doesn't do it justice. I feel that it looks much nicer than 2 months ago, and looks somewhat better in person. That said, areas previously stressed continue to show poor growth and have not thickened or recovered as quickly as hoped.

Closeup of foreground in above.

And slightly closer...

I like a little step aerator from HD to open the soil & dump that leftover milorganite to help those spots pop back