When to plant sweet corn
Sweet Corn are frost-tender: plant them out only after your last spring frost. Plant in blocks of at least four rows, not one long row, so the plants pollinate each other.
- Sow seeds outdoors 1–3 weeks after the last spring frost.
About 80 days from planting to harvest.
Get exact dates for your garden
Planting dates by hardiness zone
| Zone | Typical last frost | Start indoors | Sow outdoors | Fall crop |
|---|---|---|---|---|
| 2a | May 24 | — | May 31 – Jun 14 | — |
| 3b | May 17 | — | May 24 – Jun 7 | — |
| 4a | May 12 | — | May 19 – Jun 2 | — |
| 4b | May 8 | — | May 15 – May 29 | — |
| 5a | May 3 | — | May 10 – May 24 | — |
| 5b | May 1 | — | May 8 – May 22 | — |
| 6a | Apr 29 | — | May 6 – May 20 | — |
| 6b | Apr 22 | — | Apr 29 – May 13 | — |
| 7a | Apr 16 | — | Apr 23 – May 7 | — |
| 7b | Apr 5 | — | Apr 12 – Apr 26 | — |
| 8a | Mar 29 | — | Apr 5 – Apr 19 | — |
| 8b | Mar 16 | — | Mar 23 – Apr 6 | — |
| 9a | Mar 3 | — | Mar 10 – Mar 24 | — |
| 9b | Feb 20 | — | Feb 27 – Mar 13 | — |
| 10a | Mar 2 | — | Mar 9 – Mar 23 | — |
Zone rows use the median frost dates of all ZIP codes in that zone. Zones measure winter cold, not season length, so two places in the same zone can have frost dates weeks apart — use your ZIP code for real dates.
When to plant sweet corn in major cities
| City | Median last frost | Sow outdoors |
|---|---|---|
| Seattle, WA | Mar 13 | Mar 20 – Apr 3 |
| Portland, OR | Feb 25 | Mar 4 – Mar 18 |
| Salt Lake City, UT | Apr 25 | May 2 – May 16 |
| Denver, CO | Apr 30 | May 7 – May 21 |
| Minneapolis, MN | Apr 23 | Apr 30 – May 14 |
| Chicago, IL | Apr 10 | Apr 17 – May 1 |
| Detroit, MI | Apr 27 | May 4 – May 18 |
| Kansas City, MO | Apr 4 | Apr 11 – Apr 25 |
| Columbus, OH | Apr 20 | Apr 27 – May 11 |
| Boston, MA | Apr 4 | Apr 11 – Apr 25 |
| New York, NY | Mar 30 | Apr 6 – Apr 20 |
| Philadelphia, PA | Mar 30 | Apr 6 – Apr 20 |
| Washington, DC | Mar 29 | Apr 5 – Apr 19 |
| Charlotte, NC | Mar 30 | Apr 6 – Apr 20 |
| Nashville, TN | Apr 1 | Apr 8 – Apr 22 |
| Atlanta, GA | Mar 25 | Apr 1 – Apr 15 |
| Dallas, TX | Mar 2 | Mar 9 – Mar 23 |
Growing sweet corn: quick facts
| Frost tolerance | Tender: killed by frost; plant after the last frost |
|---|---|
| Soil temperature | at least 50°F to germinate; 60–95°F is ideal |
| Planting depth | 1–2 in |
| Spacing | 8–12 in, rows 30 in apart |
| Germination | 4–10 days |
| Days to harvest | about 80 days from planting |
Typical figures from university extension planting guides. Seed packets give the best numbers for a specific variety.