Massachusetts vegetable planting calendar 2027: frost dates and when to plant
In Massachusetts, the average last spring frost is April 4 in Boston (NOAA 1991-2020 normals). Below are planting dates for Boston for 27 common vegetables and herbs, worked out the way the Rowtime app does it: NOAA's average frost dates for the nearest weather station, with the planting rules of state extension guides. Dates are for the 2027 season.
Rowtime: Garden Planner works these dates out for your own ZIP code in Massachusetts, shows where each one comes from, and recalculates when a planting slips. Get Rowtime on the App Store.
Dates are estimates. Check your local extension office before you plant, and use your own frost records if you have them. Dates shift by a week or more within a state, so pick the city closest to your conditions.
Boston
When to plant tomatoes in Boston?
In Boston, Massachusetts, the average last spring frost is April 4 and the average first fall frost is November 9 (NOAA 1991-2020 normals, BOSTON LOGAN INTL AP station, 4.6 km from ZIP 02108). For tomatoes, start seeds indoors March 9 to May 15 and plant out seedlings April 17 to August 11, following University of Maryland Extension (Home & Garden Information Center) and Purdue University Extension. Dates are for the 2027 season; sources last checked October 24, 2026.
Frost dates for Boston (02108)
- Last spring frost: Apr 4 on average, Apr 17 for a 10% risk of a later frost.
- First fall frost: Nov 9 on average, Oct 29 for a 10% risk of an earlier frost.
- USDA hardiness zone 7a (PRISM 2023 listing).
| Crop | When |
|---|---|
| Beet | Sow outdoors: Mar 20 to Apr 3 Sow outdoors for fall: Sep 3 to Oct 1 |
| Broccoli | Start seeds indoors: Feb 16 to Mar 25 Plant out seedlings: Mar 6 to Mar 20 Plant out seedlings for fall: Sep 3 to Oct 1 |
| Cabbage | Start seeds indoors: Feb 9 to Mar 8 Plant out seedlings: Mar 6 to Mar 20 Plant out seedlings for fall: Sep 3 to Oct 1 |
| Carrot | Sow outdoors: Mar 20 to Apr 3 |
| Cauliflower | Start seeds indoors: Feb 23 to Mar 25 Plant out seedlings: Mar 20 to Apr 3 Plant out seedlings for fall: Jul 10 to Aug 9 |
| Cucumber | Sow outdoors: May 1 to Aug 31 |
| Eggplant | Start seeds indoors: Mar 26 to Apr 24 Plant out seedlings: May 1 to Aug 11 |
| Green onion | Plant onion sets: Mar 6 to Mar 20 Plant out seedlings for fall: Sep 3 to Oct 1 |
| Kale | Sow outdoors: Mar 6 to Mar 20 Sow outdoors for fall: Sep 3 to Oct 1 |
| Lettuce | Sow outdoors: Mar 20 to Apr 3 Sow outdoors for fall: Sep 3 to Oct 1 |
| Melon and watermelon | Sow outdoors: May 1 to Aug 1 |
| Okra | Plant out seedlings: May 1 to Sep 5 |
| Onion | Plant onion sets: Mar 6 to Mar 20 |
| Pea | Sow outdoors: Mar 6 to Mar 20 |
| Pepper | Start seeds indoors: Mar 9 to Apr 8 Plant out seedlings: May 1 to Aug 11 |
| Potato | Plant seed potatoes: Mar 6 to Mar 20 |
| Snap bean | Sow outdoors: Apr 17 to Sep 10 |
| Spinach | Sow outdoors: Mar 6 to Mar 20 Sow outdoors for fall: Sep 3 to Oct 1 |
| Summer squash | Sow outdoors: May 1 to Sep 10 |
| Sweet corn | Sow outdoors: Apr 17 to Aug 11 |
| Sweet potato | Sprout slips indoors: Apr 9 to May 8 Plant out slips: May 1 to Jul 2 |
| Tomato | Start seeds indoors: Mar 9 to May 15 Plant out seedlings: Apr 17 to Aug 11 |
| Winter squash and pumpkin | Sow outdoors: May 1 to Aug 1 |
| Basil | Plant outdoors: May 8 to Aug 7 |
| Cilantro | Sow outdoors: Feb 8 to Apr 7 Sow outdoors for fall: Sep 17 to Oct 1 |
| Dill | Sow outdoors: Mar 23 to Apr 7 Sow outdoors for fall: Aug 2 to Sep 16 |
| Parsley | Sow outdoors: Mar 26 to Apr 24 Plant outdoors for fall: Aug 2 to Oct 1 |
Sources
Planting rules, in the order Rowtime tries them here:
- Purdue University Extension, Indiana Vegetable Planting Calendar (HO-186-W). Checked October 20, 2026.
- University of Maryland Extension (Home & Garden Information Center), Vegetable Planting Calendar for Central Maryland. Checked October 24, 2026.
- NC State Extension, Central North Carolina Planting Calendar for Annual Vegetables, Fruits, and Herbs (AG-756-01). Checked October 21, 2026.
Frost dates, locations and zones:
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991-2020 annual/seasonal (freeze probabilities).
- U.S. Census Bureau, 2025 Gazetteer Files: ZIP Code Tabulation Areas.
- PRISM Group, Oregon State University / USDA ARS, 2023 USDA Plant Hardiness Zone Map ZIP code listings. PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed 20 Oct 2026.
How the dates are worked out: a guide's rule such as "two weeks after the last frost" is applied to the station's NOAA date. Purdue's dates are 10% dates, so they are counted from the station's 10% date. When a guide gives no last date, the window closes early enough for the crop's longest days to harvest before the first fall frost. When a guide gives no first date for a fall planting, no fall window is shown. "Season too short" means the guide's window would close before it opens at this station's frost dates.
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