Grasses are traditionally divided into two types: cool-season grasses and warm-season grasses. Cool-season grasses grow well in cold northern climates, and warm-season grasses thrive in hot, humid southern summers. In the transition zone between these two areas, choosing a grass type is a bit confusing. Your local Cooperative Extension Service can help you choose a grass to meet your needs.
Choose cool-season grasses for northern climates with cold winters and coastal areas where summer temperatures rarely exceed 32.2 degrees C. Extended periods of temperatures above 32.2 degrees C cause cool-season grasses to turn brown and go dormant. They regain their colour with cooler temperatures.
Common cool-season grasses include Kentucky bluegrass, perennial ryegrass, hard fescue and tall fescue. Kentucky bluegrass recovers well from damage and wear, and it has a beautiful colour. Perennial ryegrass and tall fescue are good choices for areas that get a lot of wear, such as parks and playgrounds, and lawns where children play. Hard fescue is good for unused areas such as slopes where the grass is left unmowed. Used as a lawn grass, it grows slowly and needs less frequent mowing.
Warm-season grasses do well in areas where the ground doesn't normally freeze solid. They tolerate heat and drought better than cool-season grasses. Bermuda grass, Saint Augustine grass, buffalo grass, Zoysia grass and bahiagrass are common warm-season grasses. Bermuda grass is drought tolerant and tolerates cold temperatures better than other warm-season grasses. Saint Augustine Grass thrives in heat and bright sun. It grows fast and needs frequent mowing. Buffalo grass is a heat-tolerant grass for low-use areas. It seldom requires mowing, but the seeds are very expensive. Zoysia grass is planted as sod or plugs. When planted as plugs it takes three seasons to fill in. It makes an attractive lawn once established, and requires little mowing. Bahaigrass is good for sandy, salty and acidic soils. It is a tough grass that requires frequent mowing with a sharp blade.
There is no grass that grows well in shade, but some grasses tolerate it better than others. Let grass in shady areas grow at least a half inch taller than the rest of the lawn, and keep traffic out of shady areas. Cool-season grasses that tolerate shade include rough bluegrass, Chewings fescue and tall fescue. Warm-season grasses for shady spots include Saint Augustine, centipede, bahaigrass and Zoysia.