Region Description: Southwest Deserts
Albuquerque NM, Amarillo TX, Ciudad Juarez MEX, El Paso TX, Las Cruces NM, Las Vegas NV, Lubbock TX, Mexicali MEX, Palm Springs CA, Phoeniz AZ, Tucson AZ
The Southwestern region extends from the desert regions of Southern California, east through Las Vegas, central Arizona and New Mexico and ending in West Texas, at a north-south line drawn just west of Abilene. The southern tier stretches into northern Mexico heading west to southern California near Palm Springs.
The Southwest Deserts are characterized by extremely limited rainfall and blazing summer sun. It encompasses three distinct desert regions (high, mid, and low) with wide elevation changes. Low elevations such as near Phoenix, Arizona receive 10 inches of rainfall or less annually, but can grow subtropical plants such as date palms and oranges with supplemental irrigation. Mid-level elevations such as near Las Vegas, Nevada receive 12 to 14 inches with native plants such as Joshua tree and yucca. Higher desert elevations such as Albuquerque, New Mexico have equally limited precipitation, but includes snowfall. These areas have a range of plants such as pines and lilacs. Most precipitation occurs during winter storms that run from November to February and the "monsoon" thunderstorm season in July and August. The monsoons sweep up from Mexico, bringing rainfall, increased humidity, as well as massive thunder, lightening, and dust storms.
The Growing Season
Gardening is a year-round activity in the low desert. Although damaging frosts can occur in December and January, they're usually not long-lived and gardening can continue uninterrupted. There are two growing seasons; a cool season and a warm season. Cool season plants such as broccoli and spinach are placed out in the fall for a spring harvest. Warm season plants such as tomatoes and peppers are planted in late winter for an early summer harvest. Little gardening is done during the hottest part of summer. Mid-level elevations share the low desert's hot daytime temperatures, but have a longer winter cold period, more freezing nights, and unrelenting spring winds. Areas with colder temperatures can garden from April through October. Where temperatures are less severe, mid-level elevations can enjoy two growing seasons in spring and fall. Highdesert elevations are constrained by more severe winter weather, including snow, wind, and extended freezing temperatures. The growing season is shorter, typically lasting from late May through September.