When to plant sweet corn 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). Sweet Corn needs 60–100 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 sweet corn in Arizona: the short answer
For a spring planting, sow Mar 17 – Apr 5. Wait until the soil is at least 55°F and frost is over.
Succession sow again in Arizona: Apr 5 · Apr 19 · May 3 · May 17 · May 31 · Jun 14 · Jun 28 · Jul 12
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 sweet corn in Arizona, step by step
- Prepare the bed. It needs at least six to eight hours of direct sun a day and loose soil at least 24 inches deep, with a pH between 5.8 and 7.0. Dig in compost before planting.
- Sow outdoors (Mar 17 – Apr 5). Space plants about 10 inches apart in rows 30 inches apart, sowing seed 1.5 inches deep. It is killed by frost, so nothing goes outside until the danger has passed.
- 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: corn earworm, European corn borer, corn rootworm, raccoons. Diseases and disorders: common smut, common rust, Stewart's wilt.
- Harvest (from about May 21 – Jun 30). Sweet Corn takes 60-100 days to reach harvest. Plant in a block of at least 4 short rows, not one long row, or the ears fill unevenly. Keep sugar-enhanced and supersweet types isolated from field corn. Succeed by sowing every 2 weeks or planting early/mid/late varieties together.
Figures come from our crop data; dates use Arizona’s average frost dates. More in the full sweet corn growing guide.
Sweet Corn 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 sweet corn dates shift with them.
| Zone | Last frost | First frost | Season | Start indoors | Plant sweet corn |
|---|---|---|---|---|---|
| Zone 4 | May 10 | Sep 25 | 135 days | - | May 12 – May 31 |
| Zone 5 | Apr 30 | Oct 5 | 160 days | - | May 2 – May 21 |
| Zone 6 | Apr 15 | Oct 15 | 185 days | - | Apr 17 – May 6 |
| Zone 7 | Apr 5 | Oct 25 | 200 days | - | Apr 7 – Apr 26 |
| Zone 8 | Mar 20 | Nov 5 | 230 days | - | Mar 22 – Apr 10 |
| Zone 9 | Feb 20 | Nov 30 | 280 days | - | Feb 22 – Mar 13 |
| Zone 10 | Jan 30 | Dec 15 | 330 days | - | Feb 1 – Feb 20 |
When to plant sweet corn in nearby states
| State | Last frost | Sow |
|---|---|---|
| Arizona (this page) | March 15 | Mar 17 – Apr 5 |
| New Mexico | April 20 | Apr 22 – May 11 |
Questions gardeners in Arizona ask
When is the best time to plant sweet corn in Arizona?
Sow sweet corn in Arizona between March 17 and April 5. 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.
What is the latest I can plant sweet corn in Arizona?
About September 16. Sweet corn needs at least 60 days to mature, and frost around November 15 ends the season, so later plantings risk being cut short.
When will sweet corn planted in Arizona be ready to harvest?
Planted on time, sweet corn is usually ready from about May 21 to June 30, 60-100 days after sowing.
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.