Unlike many parts of the country where autumn signals a slowdown, our desert climate opens the door to an entirely new round of planting.
PHOENIX — As the relentless triple-digit heat finally loosens its grip on Phoenix, fall ushers in one of the best gardening seasons in the Valley of the Sun. Unlike many parts of the country where autumn signals a slowdown, our desert climate opens the door to an entirely new round of planting. From cool-season vegetables to desert-adapted fruit trees, fall gardening kicks into gear in September.
Understanding your growing zone
The Valley of the Sun sits primarily in USDA Hardiness Zones 9b to 10a. These zones reflect the average annual extreme minimum temperatures and help gardeners choose plants that can survive desert winters. In practical terms, Zone 9b means the coldest winter lows typically dip between 25–30°F, while 10a averages 30–35°F. This mild range allows for both cold-hardy crops and certain subtropical fruits to thrive.
Cool-season vegetables to plant now
Think of the fall season as “prime time” to grow vegetables that would otherwise wither in summer’s heat. According to the University of Arizona Cooperative Extension, starting in mid-September through October, gardeners can plant:
Leafy greens: Lettuce, spinach, kale, Swiss chard, and arugula
Brassicas: Broccoli, cauliflower, Brussels sprouts, and cabbage
Root crops: Carrots, beets, radishes, and turnips
Alliums: Onions, garlic, and leeks
Because our desert nights are getting longer and daytime highs will eventually settle into the 80s and 70s, these crops flourish with less stress, giving Valley gardeners crisp salads and hearty harvests well into winter.
Fruit trees for the desert landscape
Fall also marks an ideal window to plant fruit trees, giving roots time to establish before summer’s return. Popular choices for Phoenix include:
Citrus: Oranges, lemons, limes, and grapefruit are desert staples.
Stone fruit: Low-chill peaches, plums, and apricots bred for warm climates.
Fig and pomegranate: Mediterranean classics that handle heat and drought beautifully.
Nurseries across the Valley often stock their best selections in fall, aligning perfectly with the planting calendar. Your local nursery experts know what types of trees will thrive in our desert climate.
First frost: When to expect it
On average, the Phoenix area’s first frost doesn’t occur until late November to early December, and many central neighborhoods never freeze at all. Outlying suburbs like Queen Creek, Buckeye, and north Scottsdale, however, may see light frost earlier. For Zone 9b gardeners, the typical frost window runs from late-November through late February.
That means most fall plantings will grow comfortably before a chill sets in. Still, keep frost cloth or old sheets handy to cover tender plants—especially young citrus or tomatoes—when our 12News forecasts hint at overnight lows dipping near freezing.
Bottom line
Fall in Phoenix isn’t about raking leaves—it’s about digging in! With cooler nights, mild days, and a generous growing season, Valley residents can enjoy a fall garden that can thrive well into the new year.
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