2 minute read

Overview

Lawn grasses are divided into ‘cool-season’ and ‘warm-season’ based on their responses to air and soil temperatures. Both types of grass can be grown in Orange County (see the purple band in the graphic below), but neither performs well here. Choosing locally-adapted varieties and following good cultural practices is important for minimizing problems.

  • Most cool-season grasses (fine fescues, Kentucky bluegrass, ryegrass) will grow here during fall, winter, and early spring but will not survive the summer.
  • Tall fescues can persist but for a dense lawn, you should overseed every fall.

turfgrass-range SC Extension Selecting a Lawn Grass

Choosing a turfgrass

Because neither warm-season nor cool-season grasses are happy here, a good approach is to plant different turfgrasses in each microclimate of your yard. Consider:

  • desired tolerance for shade, heat, cold, and wear
  • appearance (including during dormancy)
  • fertilizer and mowing requirements
  • ease and rapidity of establishment.
Tall fescueZoysiaBermuda
Dormancysummerwinterwinter
Maintenancemediumhighhigh
Establishmentfastv slowfast
Tolerance
Shadegoodgoodv poor
Heatv goodv goodexcellent
Coldv goodgoodfair
Droughtv goodexcellentexcellent
Wearv goodv goodexcellent

Cool-season grasses

These are probably the best choice for a north- or northeast-facing slope or light shade/afternoon shade.

Within this group, the 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 tends to permit crabgrass invasion. The slower-growing, dwarf-type tall fescue varieties, especially Bonsai, also are susceptible to crabgrass invasion.

  • tall fescue — best for Orange County
  • fine fescue
  • Kentucky bluegrass
  • annual ryegrass
  • perennial ryegrass

grass chart

Warm-season grasses

These should be considered for a hot southern or western exposure, especially if there is a slope. Warm-season grasses for our area require 50–75% less water for optimal appearance and are significantly more drought-tolerant than cool-season grasses.

  • Bermuda
  • zoysia

Turfgrass behavior

Turfgrass behavior is temperature-dependent, but the response of the blade (shoot) is determined by air temperature, while the root system is controlled by soil temperature. Remember that soil temperature change lags significantly behind air temperature change.

  • Shootair temperature
  • Rootsoil temperature, top 4″
Optimum growth
Shoot
Cool-season
Warm-season

60–75°F
80–90°F

Root
Cool-season
Warm-season

50–65°F
75–85°F
Growth stops due to heat
Shoot
Cool-season
Warm-season

90°F
120°F

Root
Cool-season
Warm-season

77°F
110°F
Growth stops due to cold
Shoot
Cool-season
Warm-season

40°F
N/A

Root
Cool-season
Warm-season

33°F
50°F
Low temperature kill possible
Cool-seasonif temperature drops rapidly below 20°F
Warm-season25°F

Source: Carolina Lawns