Fig. 2. Visual quality ratings of tall fescue (TF), Kentucky bluegrass (KBG), and two hybrid bluegrasses (HBG1 and HBG2) during 2003. Ratings were on a scale from 1 (dead, brown turf) to 9 (optimum uniformity, density, and color). Dashed, horizontal line at 6 indicates acceptable quality for a home lawn. Means followed with the same letter within each respective day of year (vertical) are not significantly different (P < 0.05).

Image from Applied Turfgrass Science article:
Performance in the Transition Zone of Two Hybrid Bluegrasses Compared with Kentucky Bluegrass and Tall Fescue