|Shoot — air temperature|
|Root — soil temperature, top 4″|
if temperature drops rapidly below 20°F
Source: Carolina Lawns
Because we reside in the ‘transition zone’ where neither warm- nor cool-season grasses are happy, a good approach is to plant different turfgrasses in each microclimate of your yard. Cool-season grasses are probably the best choice for a north facing slope or light shade. Warm-season grasses should be considered for a hot southern or western exposure, especially if there is a slope. Note that warm-season grasses like hybrid Bermuda and zoysia require 50–75% less water for optimal appearance and are significantly more drought-tolerant than cool-season grasses. Before purchasing a grass, consider the desired tolerance for shade, heat, cold, and wear; appearance (including during dormancy); fertilizer and mowing requirements; and ease and rapidity of establishment.
Of the the cool-season grasses (Kentucky bluegrass, tall fescue, fine fescue), tall fescues are the best-suited to our area. Newer tall fescue varieties may be better choices because the open, upright habit of older varieties like Kentucky 31 tend to permit crabgrass invasion. The slower-growing, dwarf-type tall fescue varieties, especially Bonsai, also are susceptible to crabgrass invasion. Let NC CES help you to select the right lawn grass.
Turf-type tall fescue Fine fescue
Kentucky bluegrass Fine fescue
U Minn SULIS Selecting Cool Season Lawn Grasses