The name “Cool Season Grass” is given to a variety of grass species that thrive best in cooler temperatures and particularly in the cooler regions of the country from the central transition zone and throughout the northern U.S.
The summer temperatures in southern states are generally too hot to successfully grow most varieties of cool season grasses. The transition zone is so named because of the blending and crossover from cool to warm season grasses. Click here to see the U.S. Climate Zones of Grass Adaptation.
Notice that the grass adaptation zones are categorized differently from the USDA Plant Hardiness Zones.
Cool season grasses include forage and range grasses, ornamental grasses, turf grasses, and even cool season grassy weeds. Grass seeds are planted in the fall and will thrive best in temperatures between 65 and 75 degrees. In contrast, warm season grass seeds are planted in the spring and grow best in the warmest months.
Varieties of Cool Season Grasses
Cool season turfgrasses include bluegrasses, fescues, and ryegrasses. The turf varieties of these grasses have blade textures and color that make a beautiful lawn.
Popular forage grasses include orchardgrass, timothy, fescue, ryegrass, and brome. These forage grasses can also be found in lawns, but are usually considered a weed. Tall fescue grass and the ryegrasses have forage varieties that are much larger plants and do not have the same quality as the turf-type varieties.
Each of the turf grasses have different characteristics that separate them from other grasses. The most noticeable is its color. However, blade width, growth habits, turf density, and its ability to withstand heavy traffic are also important. Most can withstand harsh winters and a few are able to survive longer periods of hot, humid weather. If you live in a cooler part of the country, there is a grass type that will work well for you.
Cool season varieties can be started from seed much easier than most warm season grasses and the seed is generally much less expensive. Bluegrass seed and rye grass seed are among the least expensive.
