The southwestern states take in a few climatic regions. Southern AZ, NM, and west TX make up the warm arid to semi arid zones. Rainfall will range from less than 5 inches to about 20 in West Texas. Low relative humidity and sparse cloud cover prevail. The northern tier of all 4 states encompasses a transition zone and some semi-cool and semi-arid territory. East Texas fits in the warm tropical where high humidity and increased rainfall occur.
Warm-season grasses will do well in all but the highest elevations. Bermudagrass is a favorite in AZ, TX, and OK. St. Augustine will be more common in south Texas. Cool-season grasses like Kentucky bluegrass and tall fescue can be found at higher elevations of New Mexico and Texas and more so in the northern half of each state.
Each zone has its management issues. Most all turfgrass will need supplemental irrigation to keep green during the summer months. Fire ants have moved into this area and must be respected. Other insect pests include chinchbugs, white grubs, ground pearls, and fall armyworms. Crabgrass germination will be early February in southern areas and into March in the northern lawns. Diseases like brown patch and Pythium would be more of a factor in east Texas where humidity is higher.