When to Plant Sweet Corn in Maine
In Maine, the time to sow sweet corn outside runs from May 2 – May 16 in Lewiston to May 23 – Jun 6 in Sanford. In Portland, it's May 3 – May 17. The average last spring frost differs by about 3 weeks across the state (Apr 25 in Lewiston, May 16 in Sanford), so use the dates for the town nearest you.
Sow corn in blocks rather than single rows so it pollinates well. Wait for soil around 60°F.
- Sow outside: 1–3 weeks after the last frost.
Sweet Corn planting dates in Maine by city
| City | Zone | Sow outside |
|---|---|---|
| Auburn | 5b | May 2 – May 16 |
| Augusta | 5b | May 4 – May 18 |
| Bangor | 5a | May 11 – May 25 |
| Bath | 6a | May 17 – May 31 |
| Belfast | 5b | May 14 – May 28 |
| Biddeford | 6a | May 16 – May 30 |
| Brewer | 5a | May 11 – May 25 |
| Caribou | 4a | May 14 – May 28 |
| Ellsworth | 5b | May 15 – May 29 |
| Gardiner | 5b | May 8 – May 22 |
| Lewiston | 5b | May 2 – May 16 |
| Old Town | 5a | May 20 – Jun 3 |
| Portland | 6a | May 3 – May 17 |
| Presque Isle | 4a | May 21 – Jun 4 |
| Rockland | 6a | May 4 – May 18 |
| Saco | 6a | May 3 – May 17 |
| Sanford | 5b | May 23 – Jun 6 |
| South Portland | 6a | May 3 – May 17 |
| Waterville | 5b | May 9 – May 23 |
| Westbrook | 5b | May 3 – May 17 |
Calculated from each town's average (50%) frost dates, from the nearest NOAA station (1991–2020). Typical dates for the 2027 planting season, based on NOAA's 1991–2020 averages. They are long-term odds, not a forecast: always check your local forecast before planting. Zones: 2023 USDA Plant Hardiness Zone Map (USDA-ARS and Oregon State University). Not the official map; see planthardiness.ars.usda.gov.
See all frost dates in Maine, or the general guide to when to plant sweet corn.
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