Cool-Season Vegetable

When to Plant Cauliflower in Arizona

The diva of the brassica family. More temperamental than broccoli but worth the extra attention.

The Short Answer

Cauliflower are cold-tolerant and do well in Arizona's varied climate. Arizona gardeners can also plant a fall crop. Alkaline, mineral-rich desert soils. Low organic matter. Heavy amendment with compost essential....

Arizona Frost Dates

Your planting dates depend on which part of Arizona you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Northern Arizona (Flagstaff) 4b, 5a, 5b, 6a May 15 - Jun 5 Sep 15 - Oct 10
Central Arizona (Phoenix) 9a, 9b, 10a Jan 15 - Feb 10 Dec 1 - Dec 20
Southern Arizona (Tucson) 8b, 9a, 9b Feb 1 - Feb 25 Nov 20 - Dec 15

Cauliflower Planting Schedule for Arizona

Northern Arizona (Flagstaff) (Zones 4b, 5a, 5b, 6a)

Average last frost: May 15 - Jun 5 · Average first frost: Sep 15 - Oct 10

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks before frost
Fall Planting
10 wks before first frost

Central Arizona (Phoenix) (Zones 9a, 9b, 10a)

Average last frost: Jan 15 - Feb 10 · Average first frost: Dec 1 - Dec 20

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks before frost
Fall Planting
10 wks before first frost

Southern Arizona (Tucson) (Zones 8b, 9a, 9b)

Average last frost: Feb 1 - Feb 25 · Average first frost: Nov 20 - Dec 15

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks before frost
Fall Planting
10 wks before first frost

Growing Cauliflower in Arizona

Cauliflower in Arizona's Climate

Cauliflower is the most challenging brassica for subtropical zones. Temperature swings during heading cause buttoning. Only attempt during your most stable cool-weather window (November-January). Consider starting with broccoli instead — it's more forgiving in inconsistent warm-zone conditions.

Soil Considerations for Arizona

Alkaline, mineral-rich desert soils. Low organic matter. Heavy amendment with compost essential. Caliche layers may need to be broken.

Arizona Climate & Growing Season

Extreme heat in summer lowlands. Two planting seasons in Phoenix — spring and fall (summer is too hot). High elevation has traditional cold-climate seasons.

Growing season length varies across Arizona: Northern Arizona (Flagstaff) (4b, 5a, 5b, 6a) has a last frost around May 15 - Jun 5, while Southern Arizona (Tucson) (8b, 9a, 9b) sees frost end around Feb 1 - Feb 25. This difference matters for cauliflower — adjust your planting dates to match your specific region.

Growing Tips

Blanch white varieties by tying outer leaves over the head when it reaches 2 inches. Temperature swings cause buttoning.

Companion Planting

Plant cauliflower alongside these companions for better growth:

Beets Celery Onions

Keep cauliflower away from:

Strawberries Tomatoes

The Bottom Line

Cauliflower can be grown successfully across Arizona, but your exact planting dates depend on which region you're in. Northern Arizona (Flagstaff) gardeners should plan around a May 15 - Jun 5 last frost, while those in Southern Arizona (Tucson) can typically plant earlier. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Cauliflower Growing Guide National planting guide with all states Arizona Planting Calendar All plants for Arizona Cauliflower in Alabama Alabama planting dates Cauliflower in Alaska Alaska planting dates Cauliflower in Arkansas Arkansas planting dates
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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