When to plant cauliflower in Arizona
Arizona’s average last spring frost is March 15, and the first fall frost typically arrives around November 15 — about 245 frost-free days (USDA zones 4b, 5b, 6b, 7b, 8b, 9b, 10b). Cauliflower needs 60–90 days to mature, which fits comfortably within Arizona's growing season.
Arizona covers a wide range of climates, so your exact frost dates may differ from the state average by two weeks or more. For dates tuned to your town, use the calendar generator.
When to plant cauliflower in Arizona: the short answer
For a spring planting, plant out Feb 22 – Mar 11, with seeds started indoors Jan 25 – Feb 8. Seeds germinate in soil from 45 to 85°F.
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow cauliflower in Arizona, step by step
- Start seeds indoors (Jan 25 – Feb 8). Sow seeds ½ inch deep in seed-starting mix under bright light. They take 5-10 days to sprout, fastest in soil around 75°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 18 inches deep, with a pH between 6.0 and 7.5. Dig in compost before planting.
- Plant out (Feb 22 – Mar 11). Space plants about 18 inches apart in rows 30 inches apart. It tolerates a light frost but not a hard freeze. As a cool-season crop it does best before summer heat arrives in Arizona.
- Water and feed. It needs plenty of water; keep the soil evenly moist and never let it dry out.
- Watch for pests and problems. Pests: cabbage worm, cabbage looper, aphids, cabbage root maggot. Diseases and disorders: clubroot, black rot, downy mildew.
- Harvest (from about Apr 30 – May 30). Cauliflower takes 60-90 days to reach harvest. The fussiest brassica - any check from cold, heat, or drought ruins the head. Fall crops are far more reliable than spring. Blanch white types by tying leaves over the curd.
Figures come from our crop data; dates use Arizona’s average frost dates. More in the full cauliflower growing guide.
Cauliflower planting dates by USDA zone in Arizona
Arizona spans USDA zones 4b, 5b, 6b, 7b, 8b, 9b, 10b. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the cauliflower dates shift with them.
| Zone | Last frost | First frost | Season | Start indoors | Plant cauliflower |
|---|---|---|---|---|---|
| Zone 4 | May 10 | Sep 25 | 135 days | Mar 22 – Apr 5 | Apr 19 – May 6 |
| Zone 5 | Apr 30 | Oct 5 | 160 days | Mar 12 – Mar 26 | Apr 9 – Apr 26 |
| Zone 6 | Apr 15 | Oct 15 | 185 days | Feb 25 – Mar 11 | Mar 25 – Apr 11 |
| Zone 7 | Apr 5 | Oct 25 | 200 days | Feb 15 – Mar 1 | Mar 15 – Apr 1 |
| Zone 8 | Mar 20 | Nov 5 | 230 days | Jan 30 – Feb 13 | Feb 27 – Mar 16 |
| Zone 9 | Feb 20 | Nov 30 | 280 days | Jan 2 – Jan 16 | Jan 30 – Feb 16 |
| Zone 10 | Jan 30 | Dec 15 | 330 days | Dec 12 – Dec 26 | Jan 9 – Jan 26 |
When to plant cauliflower in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Arizona (this page) | March 15 | Feb 22 – Mar 11 |
| New Mexico | April 20 | Mar 30 – Apr 16 |
Questions gardeners in Arizona ask
When is the best time to plant cauliflower in Arizona?
Plant cauliflower transplants outdoors in Arizona between February 22 and March 11. That timing is set by Arizona's average last spring frost of March 15; Arizona spans several climates, so cooler and higher parts of the state run later.
When should I start cauliflower seeds indoors in Arizona?
Start seeds indoors between January 25 and February 8, about 6 weeks before the last frost, so the seedlings are ready to plant out from February 22.
Can I plant cauliflower in the fall in Arizona?
Yes. For a fall crop, start transplants between August 6 and August 23, so the crop matures in cool weather before Arizona's first frost around November 15.
When will cauliflower planted in Arizona be ready to harvest?
Planted on time, cauliflower is usually ready from about April 30 to May 30, 60-90 days after transplanting.
When is the last frost in Arizona?
On average around March 15, with the first fall frost around November 15 - about 245 frost-free days. Your town may differ by two weeks or more.