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Regional Calendars, Climate & DataDesert Southwest Planting Calendar
In the low desert the calendar is flipped from much of the country. The best growing weather is often in the cooler months, and midsummer is a season to protect plants, not to push them.
Key points
- Plan the year around two growing seasons, with a heat break in summer.
- Use shade, mulch and drip irrigation to protect crops.
- Test soil and water for salts and nutrients.
- Keep local records of frost and heat to refine your calendar.
How does the desert calendar differ from the rest of the country?
In the low desert, winters are mild and summers are extremely hot, so the main vegetable season runs through fall, winter and spring. Many gardeners plant cool-season crops in fall and early winter and warm-season crops in late winter and early spring, then rest or shade beds when summer heat peaks.
Higher desert and mountain-adjacent areas have colder winters and a shorter frost-free season, and their calendars look more like those of northern regions. Elevation changes the plan, so start with your own site and station data.
A practical first step is to sort your crops into three groups: those that want cool weather, those that want warm weather and those that tolerate extreme heat. Then place each group in the part of the year that suits it. Gardeners who plant heat-sensitive crops in summer often lose them, and the lesson usually shows up in the first season.
When do you plant in the cool months?
Leafy greens, root crops, brassicas, peas, onions and garlic fit the cool part of the year. Planting in fall lets them establish while soil is still warm, then grow through the mild winter. In many low desert areas, a light frost is possible, so keep frost cloth available for sensitive crops.
Warm-season crops such as tomatoes and peppers are often planted in late winter or early spring so they can set fruit before the extreme heat arrives. Check your state extension planting guide for the range for your area, because dates vary widely across the desert.
- Fall: greens, roots, brassicas, onions, garlic
- Late winter to spring: tomatoes, peppers, squash
- Keep frost cover handy for cold snaps
How do you deal with summer heat?
Extreme heat stops fruit set on many crops, scorches leaves and dries soil quickly. Shade cloth, mulch and drip irrigation reduce stress, and some growers plant heat-adapted crops such as okra, southern peas, sweet potatoes and certain melons for the hottest months.
Water in the early morning to limit evaporation and leaf burn. Follow local water rules, which can be strict in desert communities and change with drought conditions. Keep notes on which crops survive your summer so you can refine next year's plan.
Seedlings are especially vulnerable. Shade cloth over new transplants, a layer of mulch and watering at the right time of day protect roots from heat stress. Many growers move plantings to the east side of a structure or tree so they get morning sun and afternoon shade.
What does the monsoon change?
In parts of the Southwest, a summer monsoon brings humidity, storms and sudden downpours. Rain can help cool the air and refresh soil, but it can also cause flooding, erosion and fungal problems. Some growers time a second warm-season planting to the monsoon rains and the end of peak heat.
Watch National Weather Service forecasts for storm warnings and wind. Secure row cover, trellises and shade structures before storms.
How do soil and water quality change your plan?
Desert soils are often alkaline, low in organic matter and sometimes high in salts. Irrigation water can add salts over time, which stresses plants. A soil test and, where appropriate, a water test give you a starting point, and your extension office can interpret results and suggest local approaches.
Add organic matter and mulch to improve soil structure and moisture holding, and use fertilizer only according to soil test recommendations. Nutrient management rules vary by state, so follow your state guidance.
How do you handle desert pests and wildlife?
Heat, dry air and sparse vegetation change which pests appear. Birds, rabbits, rodents and insects can all be active, and netting or fencing can protect seedlings. For insect and disease problems, identify the cause first and ask extension for current recommendations.
Any pesticide use must follow the label, observe pre-harvest intervals and protect pollinators. Applicator licensing varies by state, so check your state department of agriculture.
How do you build a Desert Southwest calendar?
For example, if your first fall frost usually falls in late November or never arrives, you might sow hardy greens in early fall and plant tender crops after the risk of frost has passed in late winter, then plan a heat-tolerant crop for midsummer. This shows the method and is not a date recommendation for your site.
Record your last and first frost, the hottest weeks, planting dates and results. After a few seasons you will see your own site's pattern, which is a better guide than any generic table. Confirm local details with your county extension office.
Share your records with neighbors and your extension office. Local knowledge on soil, water and timing builds up quickly when growers compare notes, and it often catches things that published guides miss.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.