Cool-Season Vegetable

When to Plant Broccoli in Arizona

A nutrition powerhouse that thrives in cool weather. Harvest the main head, then enjoy weeks of side shoots.

The Short Answer

Broccoli are cold-tolerant and do well in Arizona's varied climate. You can direct sow 4 weeks before your last frost — that's as early as May 15 - Jun 5 in Northern Arizona (Flagstaff). 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

Broccoli 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
Direct Sow
4 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
Direct Sow
4 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
Direct Sow
4 wks before frost
Fall Planting
10 wks before first frost

Growing Broccoli in Arizona

Broccoli in Arizona's Climate

Broccoli requires precise timing in subtropical zones. Plant in October-November for winter harvest. Your cool season may not be cold enough for optimal heading — choose varieties bred for warm-climate production. Diamondback moth and cabbage looper are aggressive year-round in mild climates, requiring more vigilant pest management than in cold zones where winter kills pest populations.

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. Broccoli can handle frost well, which is an advantage in Arizona's climate. You can push planting dates earlier in spring and extend into fall.

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 broccoli — but broccoli handle frost well, so the timing difference is less critical.

Growing Tips

Harvest main head while buds are tight. Side shoots will continue producing for weeks after the main harvest.

Companion Planting

Plant broccoli alongside these companions for better growth:

Beets Celery Onions Potatoes

Keep broccoli away from:

Tomatoes Peppers Strawberries

The Bottom Line

Broccoli 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

Broccoli Growing Guide National planting guide with all states Arizona Planting Calendar All plants for Arizona Broccoli in Alabama Alabama planting dates Broccoli in Alaska Alaska planting dates Broccoli 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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