Choosing Grass: Cool-Season Grasses
The fundamental structure of a garden is based on a selection of healthy, well-trimmed shrubs, a few gracious trees and if space and water supplies allow, a lush, rolling lawn.
Most lawn grasses are known either as cool-season (for the northern and mountain regions of the US Zones 3 through 6) or warm-season (for the southern half to third, Zones 7 through 10). Talk to your Cooperative Extension Service or local nursery and garden center about the best grass or combination of grasses for your lawn.
Cool-Season Grasses
Kentucky Bluegrass, with its blue-green hue is the most popular cool-season grass. It grows best in areas with mild summers and ample rainfall. Other cool-season grasses include:
Perennial Rye
Most often mixed with Kentucky bluegrass. Deep green and glossy, it sprouts quickly and grows in clumps.
Fescues
Red fescue starts as a fine-textured bunch grass that develops into a solid mat. It performs well in dry soils and in sun and shade. Hard fescue is slower-growing but require little maintenance. Both fescues are best used in mixtures with other grasses such as Kentucky bluegrass. A fine fescue such as ‘Highlight Chewings’ is medium green and fine-bladed. Moderately disease-resistant, it tolerates low-mowing, which is fatal to most fescues.
Original Source: http://www.cthomesllc.com/2010/10/choosing-grass-cool-season-grasses/