Soil and Climatic Tolerance

Most grasses do best in soil that is moderately fertile, neutral to slightly acidic, well-aerated and moist, and well-drained. Nevertheless, there are sites in every state and county that fall short of those ideal condi­tions. Some species can adapt to a wide range of soil conditions whereas others are very limited in adaptability.

Similarly, some grasses tolerate high humidity and reduced sunlight; others do not. Some prefer droughty climates; most do not. Some thrive in the subtropics and tropics and others are better suited for temperate and subarctic regions.

Grasses are often grouped into two categories based on the tem­peratures at which they grow best:

1. Cool-season grasses are favored by daytime temperatures of 60° to 75° F.

2. Warm-season grasses are favored by daytime temperatures of 80° to 95° F.

Knowledge of their preferred growing temperatures explains why lawns in northern states are often brown and dormant in midsummer when the days are very warm. In early spring and late fall, when temper­atures in the southern states drop, warm-season grasses do not flourish there (Figures 13-2 and 13-3).

Temperature (°F)

figure 13-2. Relationship of temperature to growth rate for cool-season and warm-season grasses (Courtesy United States Department of Agriculture)

2 3

Climatic Regions in Which the
Following Grasses Are Suitable for Lawns:

□ 1. Kentucky Bluegrass, Red Fescue, □ 4. Nonirrigated Areas: Crested Wheat, and Colonial Bentgrass. Tall Fescue, Buffalo, and Blue Grama Grasses.

Bermuda, and Zoysia Grasses in Irrigated Areas: Kentucky Bluegrass

the Southern Part. and Red Fescue.

figure 13-3. Regions of grass adaptations (Courtesy United States Department of Agriculture)