Turfgrass Climate zones, more accurately called Turfgrass Adaptation zones, are a description of general temperature and humidity conditions in specific areas as it relates to turfgrass. Turfgrass adaptation zones are structured very differently than plant hardiness climate zones. Turfgrass climate zones are grouped according to “Temperature/Humidity” variations. The U.S. has five primary turfgrass adaptation zones, as follows:
- Cool/Humid
- Warm/Humid
- Cool/Arid
- Warm/Arid
- Transition Zone
The Transition Zone isn’t a true climate zone, but was added because of the extreme variations found here. This climate zone stretches across the central part of the country. Warm season grass give way to cool season grasses within this zone. However, it is not as cut and dry as it sounds due to the range of summer and winter temperatures, humidity, and other conditions within this zone. The transition zone is considered to be the most difficult area in the U.S. to grow quality turfgrass.
Climate Zones and Preferred Grasses
The Cool/Humid Climate Zone in the northwest coastal area can receive a great deal of rainfall. That can be problematic for some grass types because of prolonged soil moisture. The fescues, bluegrass, and ryegrass are common lawn grasses in that area. The State of Oregon is known for its production of high quality turf type fescues. Although the mild temperatures of the northeast favor cool season grasses, zoysiagrass and buffalograss can be found in the drier parts in the zone.
The second Cool/Humid Climate Zone is the larger of the two cool/humid sections. The range is from the Mid-West extending throughout the northeast. Cool season grasses, including fescues, bluegrasses, and ryegrasses dominate in this area. Warm season grasses are not favored as much in this area because the summers are too short and the winters are too long and cold. It is too wet for buffalograss to survive in this area.
The Cool/Arid Climate Zone is best suited for some cool season grasses. Water usage can be high during summer for some species. Certain varieties of winter hardy Zoysia can be found here. In this area Buffalo grass is becoming a preferred turfgrass species. It originated in this cool/arid part of the U.S. and thrives in dry climates. There are many improved varieties that make a beautiful turf.
The Warm/Arid Climate Zone of the southwest is best suited for warm season grasses, including bermudagrass, zoysiagrass, buffalograss, and bahai grass. Turf-type tall fescue lawns are common in Southern California. However, in this hot, dry climate, the grass is a high water user.
The Warm/Humid Climate Zone of the southern U.S. is specifically adapted to warm season grasses, with the exception of buffalograss. Bermudagrass, zoysiagrass, St. Augustinegrass, Centipedegrass and others are grown here, keeping with their preferred temperature ranges. Annual ryegrass is sometimes seeded over bermudagrass in winter to provide some green color.
The Transition Zone is a special zone in the central portion of the U.S. This zone was added because of the extreme temperature and other variations in this area. The winters are too cold for many warm season grasses and too hot for some cool season grasses. Along the center of the zone the challenges are even greater. For example, Southern Missouri lawns are predominately fescue, while just over the border in Arkansas, it changes to predominately bermudagrass. The transition zone can extend for 300 miles north to south in some areas and extends from eastern New Mexico to the Atlantic Ocean.
Choosing the right grass type for your area is very important. Keep in mind that some grasses will have different cultivars (varieties) that were developed for growth in specific conditions. Spending time researching different varieties may prove to be a wise investment. Choosing the right variety can save you a lot of additional expense and time fixing or replanting your lawn.
Source by Russ James