Briefly:
* Avoid core aeration this time of year
* DO NOT fertilize tall fescue at this time
* Water as needed to avoid drought
* It is NOT necessary to remove thatch at this time
* Avoid the use of herbicides
* Check for brown patch disease and/or grubs July through August
* Keep lawn mowed at 3.5" to 4" tall
http://www.turffiles.ncsu.edu/turfgrasses/fine-fescue/lawn-maintenance