Leominster, MA planting zone & frost dates
Leominster is in USDA hardiness zone 6a. The last spring frost usually comes around April 29 and the first fall frost around October 11, for a growing season of about 164 days.
Planting calendar for Leominster
Dates are counted from the average last spring frost (April 29) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Mar 4 – Mar 18 Transplant outdoors: May 6 – May 13 |
| Peppers | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: May 13 – May 20 |
| Eggplant | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: May 13 – May 20 |
| Broccoli | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: Apr 1 – Apr 15 |
| Cabbage | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: Apr 1 – Apr 15 |
| Onions (sets) | Plant outdoors: Apr 1 – Apr 15 |
| Peas | Sow outdoors: Mar 18 – Apr 1 |
| Spinach | Sow outdoors: Mar 18 – Apr 1 |
| Lettuce | Sow outdoors: Apr 1 – Apr 15 |
| Carrots | Sow outdoors: Apr 1 – Apr 15 |
| Potatoes | Plant outdoors: Apr 1 – Apr 15 |
| Beans | Sow outdoors: May 6 – May 13 |
| Sweet corn | Sow outdoors: May 6 – May 13 |
| Cucumbers | Sow outdoors: May 6 – May 13 |
| Squash & zucchini | Sow outdoors: May 6 – May 13 |
| Basil | Start seeds indoors: Mar 18 – Apr 1 Transplant outdoors: May 6 – May 13 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 16 (8 weeks before the average first fall frost on Oct 11).
Useful for zone 6a gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Cold frame / mini greenhouse — adds weeks to a short season
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 19 | Apr 29 | May 13 |
| First 32°F frost in fall is before | Oct 27 | Oct 11 | Oct 1 |
How to read it: in spring there is a 10% chance of a frost after May 13, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 1. A hard freeze (28°F) usually ends around April 16.
Hardiness zone by ZIP code in Leominster
- 01453 zone 6a
Nearby cities
- Fitchburg zone 6a, last frost May 1
- Holden zone 6b, last frost Apr 23
- Shrewsbury zone 6a, last frost Apr 23
- Hudson zone 6b, last frost May 2
- Gardner zone 5b, last frost May 2
- Worcester zone 6a, last frost Apr 23
- Marlborough zone 6b, last frost May 2
- Leicester zone 6b, last frost Apr 23
Questions
What growing zone is Leominster, MA?
Leominster is in USDA Plant Hardiness Zone 6a (average extreme winter low -10°F to -5°F), according to the USDA 2023 map.
When is the last frost in Leominster?
The average last spring frost (32°F) in Leominster is April 29. There is still a 10% chance of frost until May 13.
When can I plant tomatoes in Leominster?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 6 – May 13. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Fitchburg Muni Ap, MA (USW00004780), 3.0 km (1.9 mi) from the city center, elevation 106 m, based on 22 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.