Seeding to repair bare spots can be done from mid to late August through mid October. Fertilizer is prohibited between November 15 and March 1. See our website on fertilizer. http://extension.umd.edu/hgic/soils/fertilizer
Take a look at the publication on Turfgrass Maintenance and Table 1 for
UME Turf Fertilizer Recommendations and dates of application.
For tall fescue this is September/October or before November 15.