That looks like skunks or other animals digging to get the grubs (or earthworms or other insects). Or squirrels and other animals digging things in for the winter, you'll get those as well in late September and (in 30 minutes for me) October.

You probably took care of the issue if it was grubs, so that's that. If the damage continues, check by lifting about 1 square foot of turf in an area with damage and looking for grubs. If you see 10 to more than 10 or so, treat again (use a different insecticide, though, as any grubs may have become resistant to triazicide).

Numbers less than 10 per square foot won't do enough damage to bother treating.

I see no other current evidence of disease, but it does kind of look like your lawn's going to sleep a bit early, wants to be fed, and is growing shoes. :-)

I'll post a picture tomorrow but, 70% of the lawn is pretty good and has a nice green color to it. The remainder 30% looks like this picture and/or has grass pulling right out of the ground, thess were all areas where I found a grub or two but, def not 10 per square foot. I cleared out majority of the dead stuff and re-seeded. Fingers crossed I still get good germination.

I put down OceanGro mid September...a little later than I wanted to. Hoping to try out the iron sulfate on the lawn soon. I normally don't put down a mid-late Fall fertilizer but I think I might this year to give the lawn a little something extra.

By the way, totally off topic but, do you continue to put kelp on your lawn in the Fall?

I just did a kelp app ten days ago or so, but it was definitely the last one and really only because I had time and temps are holding pretty warm.

Morph, where do you get kelp? Do you buy it dry or wet? Years ago I looked into buy North Sea kelp from a company in Canada. They sold it dry in a box for $50 for 50 pounds. Once it was moist it turned into barrels and barrels of liquid kelp for gardening. They mostly sold it to livestock producers who fed it directly to cattle.

I tend to use kelp powder and apply it as an extract; Kelp4Less and the water soluble stuff, in fact.

Morph, again. At $10 per pound dry, after you do the dilution, what does that work out to per 1,000 square feet?

One ends up using about 1/4 pound per gallon, which then becomes 4 ounces per thousand.

So: $10 per pound, $2.50 per gallon. 128 oz. 4 oz is 3.125% of 1 gallon, which is $2.50x0.03125= $0.078

Or, seven point eight cents per thousand square feet per application for the lawn.

For me, anyway, the lawn's secondary. I did/will do it three times this year, grand total cost about two dollars fifty (I go heavy on 10K). I use it in the gardens at slightly below 4 ounces per thousand per month to enhance growth and blooming.

It seems to work well on both the lawn and gardens, but assists the lawn best when applied just before times of stress--so a few weeks before summer, and in fall before winter.