The demand for year-round, high quality sports turf surfaces has resulted in the practice of overseeding becoming more common where warm-season turfgrasses are managed. The most common turf species used in overseeding is perennial ryegrass (Lolium perenne L.), which is typically seeded when bermudagrass (Cynodon dactylon Pers., C. dactylon x transvaalensis Burtt-Davy) enters dormancy. Ideally the overseeded species will naturally die out when temperatures warm and bermudagrass has broken dormancy. However, improvements in the heat and disease tolerance of perennial ryegrass cultivars have increased the tendency of this species to behave as a perennial and persist late into the summer and interfere with bermudagrass green-up following dormancy (Horgan and Yelverton, 2001). Recent breeding efforts have resulted in two species new to the turf industry that have turf quality characteristics similar to perennial ryegrass, but with relatively poor heat tolerance (Richardson et al., 2007). Both tetraploid perennial ryegrass (Lolium perenne L. 2n=4x=28) and meadow fescue (Festuca pratensis Huds.) have shown promise for use as overseeding species due to good turf quality and early transition back to bermudagrass (Richardson et al., 2007). Little is known about the cultural practices necessary to maximize turf quality for these two species. The objective of this research was to determine the effects of mowing height and nitrogen (N) fertility rate on the quality and coverage of overseeded meadow fescue and tetraploid perennial ryegrass under trafficked and non-trafficked conditions.