New London, CT planting zone & frost dates
New London is in USDA hardiness zone 7a. The last spring frost usually comes around April 8 and the first fall frost around November 2, for a growing season of about 207 days.
Planting calendar for New London
Dates are counted from the average last spring frost (April 8) 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: Feb 11 – Feb 25 Transplant outdoors: Apr 15 – Apr 22 |
| Peppers | Start seeds indoors: Jan 28 – Feb 11 Transplant outdoors: Apr 22 – Apr 29 |
| Eggplant | Start seeds indoors: Jan 28 – Feb 11 Transplant outdoors: Apr 22 – Apr 29 |
| Broccoli | Start seeds indoors: Jan 28 – Feb 11 Transplant outdoors: Mar 11 – Mar 25 |
| Cabbage | Start seeds indoors: Jan 28 – Feb 11 Transplant outdoors: Mar 11 – Mar 25 |
| Onions (sets) | Plant outdoors: Mar 11 – Mar 25 |
| Peas | Sow outdoors: Feb 25 – Mar 11 |
| Spinach | Sow outdoors: Feb 25 – Mar 11 |
| Lettuce | Sow outdoors: Mar 11 – Mar 25 |
| Carrots | Sow outdoors: Mar 11 – Mar 25 |
| Potatoes | Plant outdoors: Mar 11 – Mar 25 |
| Beans | Sow outdoors: Apr 15 – Apr 22 |
| Sweet corn | Sow outdoors: Apr 15 – Apr 22 |
| Cucumbers | Sow outdoors: Apr 15 – Apr 22 |
| Squash & zucchini | Sow outdoors: Apr 15 – Apr 22 |
| Basil | Start seeds indoors: Feb 25 – Mar 11 Transplant outdoors: Apr 15 – Apr 22 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 7 (8 weeks before the average first fall frost on Nov 2).
Useful for zone 7a 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
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Mar 28 | Apr 8 | Apr 22 |
| First 32°F frost in fall is before | Nov 15 | Nov 2 | Oct 18 |
How to read it: in spring there is a 10% chance of a frost after April 22, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 18. A hard freeze (28°F) usually ends around March 29.
Hardiness zone by ZIP code in New London
- 06320 zone 7a
Nearby cities
- Waterford zone 7a, last frost Apr 16
- Ledyard zone 6b, last frost Apr 8
- Montville Center zone 6b, last frost Apr 14
- Norwich zone 6b, last frost Apr 14
- Old Saybrook zone 7a, last frost Apr 6
- Windham zone 6b, last frost Apr 28
- Plainfield zone 6b, last frost Apr 30
- Willimantic zone 6b, last frost Apr 28
Questions
What growing zone is New London, CT?
New London is in USDA Plant Hardiness Zone 7a (average extreme winter low 0°F to 5°F), according to the USDA 2023 map.
When is the last frost in New London?
The average last spring frost (32°F) in New London is April 8. There is still a 10% chance of frost until April 22.
When can I plant tomatoes in New London?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 15 – Apr 22. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Groton, CT (USC00063207), 5.2 km (3.2 mi) from the city center, elevation 12 m, based on 24 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.