Nashua, NH planting zone & frost dates

Nashua is in USDA hardiness zone 6a. The last spring frost usually comes around April 30 and the first fall frost around October 12, for a growing season of about 165 days.

USDA hardiness zone6aavg. extreme winter low -10°F to -5°F
Average last spring frostApril 3090% chance of no frost after May 11
Average first fall frostOctober 1210% chance of frost by September 30
Growing season165 daysfrost-free days in an average year

Planting calendar for Nashua

Dates are counted from the average last spring frost (April 30) 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.

CropWhen
TomatoesStart seeds indoors: Mar 5 – Mar 19
Transplant outdoors: May 7 – May 14
PeppersStart seeds indoors: Feb 19 – Mar 5
Transplant outdoors: May 14 – May 21
EggplantStart seeds indoors: Feb 19 – Mar 5
Transplant outdoors: May 14 – May 21
BroccoliStart seeds indoors: Feb 19 – Mar 5
Transplant outdoors: Apr 2 – Apr 16
CabbageStart seeds indoors: Feb 19 – Mar 5
Transplant outdoors: Apr 2 – Apr 16
Onions (sets)Plant outdoors: Apr 2 – Apr 16
PeasSow outdoors: Mar 19 – Apr 2
SpinachSow outdoors: Mar 19 – Apr 2
LettuceSow outdoors: Apr 2 – Apr 16
CarrotsSow outdoors: Apr 2 – Apr 16
PotatoesPlant outdoors: Apr 2 – Apr 16
BeansSow outdoors: May 7 – May 14
Sweet cornSow outdoors: May 7 – May 14
CucumbersSow outdoors: May 7 – May 14
Squash & zucchiniSow outdoors: May 7 – May 14
BasilStart seeds indoors: Mar 19 – Apr 2
Transplant outdoors: May 7 – May 14

Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 17 (8 weeks before the average first fall frost on Oct 12).

Useful for zone 6a gardens

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Frost risk in detail

90% chance50% chance10% chance
Last 32°F frost in spring is afterApr 18Apr 30May 11
First 32°F frost in fall is beforeOct 28Oct 12Sep 30

How to read it: in spring there is a 10% chance of a frost after May 11, so that is a safe date for tender plants. In fall there is a 10% chance of frost before September 30. A hard freeze (28°F) usually ends around April 17.

Hardiness zone by ZIP code in Nashua

Nearby cities

All cities in New Hampshire → · Other zone 6a cities →

Questions

What growing zone is Nashua, NH?

Nashua 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 Nashua?

The average last spring frost (32°F) in Nashua is April 30. There is still a 10% chance of frost until May 11.

When can I plant tomatoes in Nashua?

Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 7 – May 14. Start seeds indoors 6–8 weeks before the last frost.

Frost dates: NOAA U.S. Climate Normals 1991–2020, station Nashua 2 Nnw, NH (USC00275712), 2.9 km (1.8 mi) from the city center, elevation 41 m, based on 26 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.