Calendars by city / ME
Portland, Maine vegetable planting calendar
Planting windows for Portland, Maine built from the NOAA 1991–2020 freeze normals at PORTLAND INTERNATIONAL JETPORT, ME US (station USW00014764), not from a hardiness zone.
Portland, Maine planting dates for 27 vegetables
The same windows as a table
Each row applies a published extension rule to the frost dates above. Hardy crops go out 2–4 weeks before the last frost; semi-hardy crops 0–2 weeks before; tender crops around the frost date; very tender crops 2 or more weeks after. The last fall planting date counts the crop's days to harvest back from the first fall frost. The rules and their sources are on the methodology page.
| Crop | Frost class | Start seeds indoors | Plant outdoors | Last fall planting | Days to harvest |
|---|---|---|---|---|---|
| Beets | Semi-hardy | — (direct sow) | Direct sow: Apr 17 – May 1 | Aug 18 | 60 |
| Broccoli | Hardy | Feb 13 – Mar 13 | Transplant: Apr 3 – Apr 17 | Aug 20 | 65 (from transplant) |
| Cabbage | Hardy | Feb 13 – Mar 13 | Transplant: Apr 3 – Apr 17 | Jul 31 | 85 (from transplant) |
| Carrots | Semi-hardy | — (direct sow) | Direct sow: Apr 17 – May 1 | Aug 8 | 70 |
| Cauliflower | Semi-hardy | Feb 27 – Mar 27 | Transplant: Apr 17 – May 1 | Aug 13 | 65 (from transplant) |
| Kohlrabi | Hardy | — (direct sow) | Direct sow: Apr 3 – Apr 17 | Sep 4 | 50 |
| Lettuce (leaf) | Hardy | — (direct sow) | Direct sow: Apr 3 – Apr 17 | Aug 25 | 60 |
| Onions (green) | Hardy | — (direct sow) | Direct sow: Apr 3 – Apr 17 | Aug 25 | 60 |
| Onions (dry, from seed) | Hardy | — (direct sow) | Direct sow: Apr 3 – Apr 17 | Jul 6 | 110 |
| Onions (dry, from sets) | Hardy | — (direct sow) | Plant sets: Apr 3 – Apr 17 | Jul 6 | 110 |
| Parsnips | Semi-hardy | — (direct sow) | Direct sow: Apr 17 – May 1 | Aug 8 | 70 |
| Peas | Hardy | — (direct sow) | Direct sow: Apr 3 – Apr 17 | Aug 20 | 65 |
| Potatoes | Semi-hardy | — (direct sow) | Plant seed potatoes: Apr 17 – May 1 | Jun 14 | 125 |
| Radishes | Hardy | — (direct sow) | Direct sow: Apr 3 – Apr 17 | Sep 24 | 30 |
| Spinach | Hardy | — (direct sow) | Direct sow: Apr 3 – Apr 17 | Sep 14 | 40 |
| Swiss chard | Semi-hardy | — (direct sow) | Direct sow: Apr 17 – May 1 | Aug 18 | 60 |
| Turnips | Hardy | — (direct sow) | Direct sow: Apr 3 – Apr 17 | Sep 4 | 50 |
| Snap beans | Tender | — (direct sow) | Direct sow: May 1 – May 8 | Aug 11 | 60 |
| Cantaloupe | Very tender | Apr 24 – May 15 | Direct sow (or transplant): May 15 – May 29 | Jul 17 | 85 |
| Sweet corn | Tender | — (direct sow) | Direct sow: May 1 – May 8 | Jul 12 | 60–90 |
| Cucumbers | Tender | Apr 10 – Apr 24 | Direct sow (or transplant): May 1 – May 8 | Aug 16 | 55 |
| Eggplant | Very tender | Mar 13 – Apr 17 | Transplant: May 15 – May 29 | Aug 11 | 60 (from transplant) |
| Peppers | Very tender | Mar 20 – Apr 17 | Transplant: May 15 – May 29 | Aug 1 | 70 (from transplant) |
| Tomatoes | Very tender | Mar 27 – Apr 24 | Transplant: May 15 – May 29 | Aug 6 | 65 (from transplant) |
| Summer squash | Tender | Apr 10 – Apr 24 | Direct sow (or transplant): May 1 – May 8 | Aug 21 | 50 |
| Winter squash | Very tender | Apr 24 – May 15 | Direct sow (or transplant): May 15 – May 29 | Jul 2 | 100 |
| Watermelon | Very tender | Apr 24 – May 15 | Direct sow (or transplant): May 15 – May 29 | Jul 17 | 85 |
What the Portland, Maine frost-free season means for your choices
At 162 frost-free days, Portland, Maine gardeners should compare that number to the days-to-harvest column before buying seed. A crop whose days to harvest plus its transplant age is close to the season length needs either an early start indoors or a short-season variety.
- Hardy crops (peas, spinach, radishes, lettuce, broccoli, cabbage) can go in from about Apr 3 – Apr 17 and again for fall.
- Very tender crops (tomatoes, peppers, eggplant, melons, winter squash) should wait until May 15 – May 29; start tomato seeds indoors Mar 27 – Apr 24.
- Fall sowing is worthwhile only for the rows that show a separate fall date; for the others the spring window already covers the season.
Portland, ME planting questions
When is the last frost in Portland, Maine?
The 50% probability date for the last spring 32°F reading at PORTLAND INTERNATIONAL JETPORT, ME US is May 1, from the NOAA 1991–2020 climate normals. In half the years on that record the last frost came later than that date, so tender crops are safer a week or two after it. The last 28°F hard freeze averages Apr 18.
When can I plant tomatoes in Portland, Maine?
Tomatoes are a very tender crop, so the Colorado State Extension rule puts them out 2 or more weeks after the last spring frost: May 15 – May 29 in Portland, Maine. Start the seeds indoors Mar 27 – Apr 24, which is 5 to 7 weeks before that transplant window.
How long is the growing season in Portland, Maine?
Portland, Maine averages 162 frost-free days, between the 50% last spring frost on May 1 and the 50% first fall frost on Oct 10 at PORTLAND INTERNATIONAL JETPORT, ME US. Check a variety's days to harvest against that number before buying seed.
When should I start seeds indoors in Portland, Maine?
The earliest indoor sowing on this calendar is broccoli and cabbage at Feb 13 – Mar 13. Hardy crops are transplanted out Apr 3 – Apr 17 here, and each crop's indoor window is simply its outdoor window minus the transplant age published by Colorado State Extension, so nothing starts earlier than that.
What can I plant in fall in Portland, Maine?
The crops with a separate fall sowing here, latest first, are radishes, spinach, kohlrabi, turnips, lettuce (leaf) and onions (green), plus 21 more on the chart above. Each fall date counts the crop's days to harvest back from the first fall frost on Oct 10, plus an allowance for frost-tolerant crops that is our own assumption, not the source's.
Station data and limitations
| NOAA station | PORTLAND INTERNATIONAL JETPORT, ME US (USW00014764) |
|---|---|
| Location | 43.6497, -70.3002 · elevation 13.7 m |
| Last spring 32°F / 28°F (50%) | May 1 / Apr 18 |
| First fall 32°F / 28°F (50%) | Oct 10 / Oct 21 |
| Dataset | NOAA/NCEI U.S. Climate Normals 1991–2020, annual/seasonal product, data types ANN-TMIN-PRBLST/PRBFST-T32FP50 and T28FP50 |
| Retrieved | 2026-10-16 |
The normals describe the airport station, not your yard. They are averages of a 30-year record and say nothing about this year's weather. Watch the local forecast around the dates shown, and use soil temperature for warm-season crops, which the Colorado State guide treats as the better signal.
Nearby calendars
- Concord, New Hampshire — last spring frost May 13
- Boston, Massachusetts — last spring frost Apr 6
- Burlington, Vermont — last spring frost May 4
- Hartford, Connecticut — last spring frost Apr 24
Read the method behind these dates: last frost date vs hardiness zone.