When to Plant Tomatoes in Maine
In Maine, the time to transplant tomatoes 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.
Tomatoes are killed by frost and sulk in cold soil. Wait until nights stay above 50°F, usually one to three weeks after the average last frost.
- Start indoors: 6–8 weeks before the last frost.
- Transplant outside: 1–3 weeks after the last frost.
Tomatoes planting dates in Maine by city
| City | Zone | Start indoors | Transplant outside |
|---|---|---|---|
| Auburn | 5b | Feb 28 – Mar 14 | May 2 – May 16 |
| Augusta | 5b | Mar 2 – Mar 16 | May 4 – May 18 |
| Bangor | 5a | Mar 9 – Mar 23 | May 11 – May 25 |
| Bath | 6a | Mar 15 – Mar 29 | May 17 – May 31 |
| Belfast | 5b | Mar 12 – Mar 26 | May 14 – May 28 |
| Biddeford | 6a | Mar 14 – Mar 28 | May 16 – May 30 |
| Brewer | 5a | Mar 9 – Mar 23 | May 11 – May 25 |
| Caribou | 4a | Mar 12 – Mar 26 | May 14 – May 28 |
| Ellsworth | 5b | Mar 13 – Mar 27 | May 15 – May 29 |
| Gardiner | 5b | Mar 6 – Mar 20 | May 8 – May 22 |
| Lewiston | 5b | Feb 28 – Mar 14 | May 2 – May 16 |
| Old Town | 5a | Mar 18 – Apr 1 | May 20 – Jun 3 |
| Portland | 6a | Mar 1 – Mar 15 | May 3 – May 17 |
| Presque Isle | 4a | Mar 19 – Apr 2 | May 21 – Jun 4 |
| Rockland | 6a | Mar 2 – Mar 16 | May 4 – May 18 |
| Saco | 6a | Mar 1 – Mar 15 | May 3 – May 17 |
| Sanford | 5b | Mar 21 – Apr 4 | May 23 – Jun 6 |
| South Portland | 6a | Mar 1 – Mar 15 | May 3 – May 17 |
| Waterville | 5b | Mar 7 – Mar 21 | May 9 – May 23 |
| Westbrook | 5b | Mar 1 – Mar 15 | 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 tomatoes.
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