Fall ushers in garden harvests and the time to feed the lawn as well as taking steps to repair damage brought on by summer heat and all the pests that harm turf and bedding plants.  Your turf-type-tall fescue grass needs a nitrogen boost applied in early fall with a repeat in late fall and again in early winter (but before the ground freezes).  Doing so allows the grass plant to store carbohydrates in the root system to ensure survival a harsh winter may impose.  Fall is also the time to do plug aeration.