Although there are a multitude of grass brands, there are basically 2 types of grass: Cool and Warm Season Grasses with each type better suited to particular climates in North America. See the MOWING section for mowing recommendations. Also see the HISTORY section for a brief history of lawns in American culture.
Cool season grasses
On average, these climates have cold winters and warm/hot summers. Usually they also have regular intervals of rain throughout the summer months, but grasses will tolerate some extended periods of draught by going dormant.
Transition zone grasses
There is a transition zone between northern and southern turf regions, which follows the lower elevations of Virginia and North Carolina west through West Virginia, Kentucky, Tennessee and Arkansas and includes southern Ohio, Indiana, Illinois, Missouri and Kansas. In this transition zone, neither warm nor cool season grasses are uniformly successful. However, several of the northern or cool season grasses, such as Kentucky bluegrass and perennial ryegrass and tall fescue, do well across Kentucky, Virginia, West Virginia and Missouri. Tall fescue is the best choice in Tennessee, North Carolina, northern Georgia, northern Alabama and the Texas panhandle. In the lower elevations of these latter states warm season grasses do well too.
Warm zone grasses
In some ways, growing and maintaining a good-looking lawn in the South is more involved than in the North. Choosing grass varieties is trickier; many grass varieties do much better when started as plugs or sod than from seed, as is usually done in the North. Good soil is critically important for growing a low maintenance lawn in this region. Most all warm weather grasses will turn brown when cooler temperatures arrive. Some southern gardeners seed their existing lawns with ryegrass each fall to maintain green color during the winter months. This is called winter overseeding.
Maintaining ideal growing conditions for your particular grass type is critical, otherwise unwanted grass varieties will start popping up and will be extremely difficult to remove. For example, St. Augustine grass being invaded by Bermuda and vice versa.
Mixtures and Blends
Cool-season grass seeds are frequently packaged in either a mixture or a blend. Mixtures have two or more species of grass, and blends contain two or more cultivars of the same species.
There are many advantages to planting a mixture or blend. For one thing, the turf will be more resistant to diseases and pests, because each cultivar or species has its own strengths and weaknesses. Since most lawns have a variety of growing conditions, different grasses can grow where they are best adapted within your lawn.
In a typical grass seed mixture containing bluegrass, ryegrass, and fine fescue, the fescues will thrive in shady portions of the lawn, while bluegrass likes sunny areas. If conditions should turn adverse for one grass, you won't lose the entire lawn, just the part that's made up of the susceptible grass.
Unlike cool-season grasses, warm-season grasses tend to be planted as monostands, meaning a single type of seed is planted, not a mixture. Their growth via stolons and rhizomes makes them so vigorous that other grasses cannot compete.
Because of their distinctive appearance, some grasses, such as the original tall fescues and most native grasses, also look better planted alone.
Grass seed labels
Thanks to the passage of the Federal Seed Act of 1936, grass-seed labeling must meet certain requirements. You'll know at a glance what is in any given box of seed, including what percentage of the seed will germinate.
When you shop for seed, compare brands closely and remember the adage, "the lawn you grow is no better than the seed you buy." The extra expense for higher-quality seed is usually worth it.
Check labels and avoid mixtures containing lower-quality grasses, like timothy, meadow fescue, orchard grass, tall oatgrass, and annual ryegrass.
Look for cultivars recommended by your Cooperative Extension Service.
While unused grass seed may remain viable for years, its germination rate decreases over time. Keep seed stored in a cool, dry environment. To maintain optimum viability, the rule of thumb for storage is that temperature and relative humidity added together should be less than 100.