Lawn Climates of North America
The United States contains nine lawn regions. The region you live in determines the type of lawn you should plant. The list here can give you guidance about the grasses to plant in your zone, but you can get more specific information from local nursery growers or your cooperative extension agency.
Zone 1 — Coastal West: Rain is generally plentiful in the Coastal West, although in the southern parts of the area it rains mostly in winter. The summers are dry. Cool-season grasses are best adapted to this region. Soils are often acidic, so you need to add lime. Tall fescues are more popular where summers are dry, as in northern California.
Zone 2 — Western transitional zone: Summers are generally long, dry, and warm in the Western transitional zone, which includes central and southern California. The winters are seasonable. You can grow either warm-season or cool-season grasses in this zone. Warm-season grasses, such as Bermuda grass, are preferable where water supplies are short. You can overseed warm-season grasses with tall fescue or ryegrass to keep lawns green in winter.
Zone 3 — Arid Southwest: The Arid Southwest zone boasts long, hot summers and relatively dry weather year-round. It includes the low elevation desert climates of California, Arizona, and New Mexico. Warm-season grasses, such as hybrid Bermuda grass and zoysia grass, are your best choices. You can overseed warm-season grasses with annual or perennial ryegrass to keep them green year-round. Plant tall fescue, as well as natives like buffalo grass, in higher elevation areas. Soils are generally alkaline.
Zone 4 — Cold and dry areas of the West: Zone 4 encompasses the cold and dry areas of the West, including high-elevation areas and the Great Plains. These climates are particularly tough, with wide fluctuations in temperature and rainfall and frequent high winds. Tough, native grasses such as buffalo grass, crested wheatgrass, and blue grama are often ideal choices. You can grow warm-season grasses in some southern areas. Otherwise, cool-season grasses such as tall fescue and Kentucky bluegrass are preferable.
Zone 5 — Midwest: The Midwest has cold, snowy winters and warm, humid summers with frequent rainfall. Cool-season grasses are widely planted, although you can find some hardier zoysia grass lawns in southern areas.
Zone 6 — Northeast: Cold, snowy winters; warm, humid summers with frequent rain; and acidic soils are the norm in the Northeast. Cool-season grasses predominate. You can grow some hardier warm-season grasses in southern coastal areas.
Zone 7 — Eastern transitional zone: Summers are generally warm and humid in the Eastern transitional zone. The winters are mild, but can be cold, especially at higher elevations. You can grow either warm-season or cool-season grasses, but local adaptation is very important because neither is perfectly suited. Overseeding warm-season grasses with cool-season grasses in fall keeps lawns green year-round. Check with the local nurserygrower or your cooperative extension service for recommendations.
Zone 8 — Central Southeast: The Central Southeast zone is warm and humid and gets plenty of rain. Soils are often acidic. Warm-season grasses such as Bermuda grass, zoysia grass, and centipede grass are well-suited. Plant tall fescue in cooler, high-elevation areas. You also can use cool-season grasses to overseed warm-season grasses to keep lawns green throughout winter.
Zone 9 — Gulf Coast, Florida, and Hawaii: Warm, humid, and wet best describes Zone 9. You get rain, rain, and more rain — diseases can run wild. Warm-season grasses are the only grasses suited for this area. Use carpet grass in particularly wet spots. Other good choices include Bermuda grass, Bahia grass, centipede grass, zoysia grass, and St. Augustine grass.