What will be good lawn seed for your lawn varies widely by climate. Some grasses spring back after cold winters, while others are best suited to high-moisture, warmer climates. These are described as cool-season or warm-season grasses. Choose one based on your local climate and the specific needs and qualities of your lawn.
Identify what grass seeds are in the product you are considering. It may be 100 all one kind of grass seed, or it could be a mix. Do not choose a seed that contains a significant percentage of annual grass seed, as this will die its first winter. Look for perennial grass seeds instead.
Check the hardiness. If you are in a warm Southern climate, buy a grass seed that will thrive in warmth and humidity. These might include: Bermuda grass, Zoysia, or St. Augustine grass. Don't choose grasses that cannot tolerate warm nights.
If you are in the North, be sure to choose a grass seed that is cold-hardy. You don't want to have to replant your lawn after a cold winter. Some cool-season varieties include: Kentucky bluegrass, red or fine fescue, tall fescue, perennial ryegrass and bentgrass.
Consider whether most of your lawn is shaded or in full sun. For instance, red fescue grows well in shade, but not in full sun or with heat and humidity. Another consideration is foot traffic; if your lawn is used for sports or play frequently, some grasses do not stand up to heavy traffic well. Check these characteristics before choosing a seed.
If you have a chance, look at the grass seed itself. It should be light, dry and free of bugs, dirt, sticks or rocks for the most part. It should not be brown, wet, dirty or have a strong odor. If you purchase a package of seed and it turns out to be rotten or mildewy, return it at once; don't try to use any part of it.