New Haven, CT planting zone & frost dates
New Haven is in USDA hardiness zone 7a. The last spring frost usually comes around April 17 and the first fall frost around October 27, for a growing season of about 193 days.
Planting calendar for New Haven
Dates are counted from the average last spring frost (April 17) 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 20 – Mar 6 Transplant outdoors: Apr 24 – May 1 |
| Peppers | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: May 1 – May 8 |
| Eggplant | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: May 1 – May 8 |
| Broccoli | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: Mar 20 – Apr 3 |
| Cabbage | Start seeds indoors: Feb 6 – Feb 20 Transplant outdoors: Mar 20 – Apr 3 |
| Onions (sets) | Plant outdoors: Mar 20 – Apr 3 |
| Peas | Sow outdoors: Mar 6 – Mar 20 |
| Spinach | Sow outdoors: Mar 6 – Mar 20 |
| Lettuce | Sow outdoors: Mar 20 – Apr 3 |
| Carrots | Sow outdoors: Mar 20 – Apr 3 |
| Potatoes | Plant outdoors: Mar 20 – Apr 3 |
| Beans | Sow outdoors: Apr 24 – May 1 |
| Sweet corn | Sow outdoors: Apr 24 – May 1 |
| Cucumbers | Sow outdoors: Apr 24 – May 1 |
| Squash & zucchini | Sow outdoors: Apr 24 – May 1 |
| Basil | Start seeds indoors: Mar 6 – Mar 20 Transplant outdoors: Apr 24 – May 1 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 1 (8 weeks before the average first fall frost on Oct 27).
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 | Apr 2 | Apr 17 | May 1 |
| First 32°F frost in fall is before | Nov 8 | Oct 27 | Oct 11 |
How to read it: in spring there is a 10% chance of a frost after May 1, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 11. A hard freeze (28°F) usually ends around April 4.
Hardiness zone by ZIP code in New Haven
- 06501 zone 7a
- 06502 zone 7a
- 06503 zone 7a
- 06504 zone 7a
- 06505 zone 7a
- 06506 zone 7a
- 06507 zone 7a
- 06508 zone 7a
- 06509 zone 7a
- 06510 zone 7a
- 06511 zone 7a
- 06512 zone 7a
- 06513 zone 7a
- 06515 zone 7a
- 06519 zone 7a
- 06520 zone 7a
- 06521 zone 7a
- 06525 zone 6b
- 06530 zone 7a
- 06531 zone 7a
- 06532 zone 7a
- 06533 zone 7a
- 06534 zone 7a
- 06535 zone 7a
- 06536 zone 7a
- 06537 zone 7a
- 06538 zone 7a
- 06540 zone 7a
Nearby cities
- West Haven zone 7a, last frost Apr 17
- East Haven zone 7a, last frost Apr 17
- Hamden zone 6b, last frost Apr 18
- Orange zone 7a, last frost Apr 25
- North Haven zone 6b, last frost Apr 18
- Branford zone 7a, last frost Apr 17
- Milford zone 7a, last frost Apr 5
- Ansonia zone 6b, last frost Apr 25
Questions
What growing zone is New Haven, CT?
New Haven is in USDA Plant Hardiness Zone 7a (average extreme winter low 0°F to 5°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 6b.
When is the last frost in New Haven?
The average last spring frost (32°F) in New Haven is April 17. There is still a 10% chance of frost until May 1.
When can I plant tomatoes in New Haven?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 24 – May 1. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station New Haven Tweed Ap, CT (USW00014758), 6.0 km (3.7 mi) from the city center, elevation 1 m, based on 19 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.