Spreading Grub-X when you have no grubs is a waste of your time, energy, and money. Is that fescue actually dying or is it going dormant for the summer as many fescues are prone to?

Creeping red fescue is a good choice under the trees because it does well with shade. It could be that you're hitting it with too much fertilizer. Creeping red fescue only needs about 1-2 lbs of N per 1000 sq ft per year and most of that should come in the fall. If you've spread corn meal, soybean meal and chicken manure, you may already be past the amount you'd need for the full year.

Hi,
Does the grass sort of look like it is melting? For years I would re-seed under and have beautiful grass under my huge Beach tree until hot humid weather arrived. Then the beautiful grass would just lay down and melt. I would mow this grass as high as possible and I would water it if there was a need. But, each year it would "melt".
I feel the problem is a soil fungus; not really a grass problem per se. Here is what helped me: Slowly over the years I removed a limb or two here and there to allow more sun in that area. I stopped watering that area. I spread corn meal (not mix) under the tree a few times a year and now, contrary to everything I have read and heard, I nearly scalp cut the grass JUST UNDER THE TREE. I feel this lets the grass and soil dry faster and helps keep the fungus at bay. Also, (stay seated) I have been known to clean the pennies out of my truckÂs ash tray, etc and toss the pre-1981 pennies (not a bunch, but just a few here and there)under the tree. TheyÂre copper and copper fights the fungus as opposed to the corn meal which, I feel, just strengthens the bacteria or whatever that already exists and is the natural enemy of the fungus.
Also, just to be sure, you may want to have the soil tested to see if it has rhizoctonia issues / brown patch disease.
best
Lou

btw. The pennies can be picked up and used/spent else where-unlike a liquid copper fungus chemical some folks use for soil fungus/brown patch.

-L