When to Plant Sweet Corn in New Hampshire
In New Hampshire, the time to sow sweet corn outside runs from May 6 – May 20 in Nashua to May 30 – Jun 13 in Berlin. In Manchester, it's May 7 – May 21. The average last spring frost differs by about 3 weeks across the state (Apr 29 in Nashua, May 23 in Berlin), 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 New Hampshire by city
| City | Zone | Sow outside |
|---|---|---|
| Berlin | 4b | May 30 – Jun 13 |
| Claremont | 5b | May 21 – Jun 4 |
| Concord | 5b | May 15 – May 29 |
| Dover | 6a | May 10 – May 24 |
| Franklin | 5b | May 14 – May 28 |
| Keene | 5b | May 21 – Jun 4 |
| Laconia | 5b | May 7 – May 21 |
| Lebanon | 5a | May 16 – May 30 |
| Manchester | 6a | May 7 – May 21 |
| Nashua | 6a | May 6 – May 20 |
| Portsmouth | 6a | May 11 – May 25 |
| Rochester | 6a | May 7 – May 21 |
| Somersworth | 6a | May 7 – May 21 |
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 New Hampshire, or the general guide to when to plant sweet corn.
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