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Seed Starting Calendar for New Hampshire

Median last frost from Apr 30 to May 27 across New Hampshire

NOAA stations
51
Median last frost, Concord
May 8
Passed in 9 of 10 years
May 22
Last frost

Last spring frost dates in New Hampshire

Nashua in the Merrimack Valley reaches its median last frost around Apr 30, Concord around May 8, and Berlin in the North Country and Keene in the Monadnock region around May 14.

Three dates per station from the NOAA 1991 to 2020 normals. The median is the date half of springs run past. The last column is the date the last 32°F night has passed by in 9 years out of 10, the one to hold tender transplants for.

StationElevationEarly (1 in 10 years later than this)Median last frostPassed in 9 of 10 yearsMedian first fall frost
NashuaNashua 2 NNW, USC00275712135 ftApr 18Apr 30May 11Oct 12
ConcordConcord Municipal Airport, USW00014745346 ftApr 27May 8May 22Oct 3
Lebanon Municipal AirportLebanon Municipal Airport, USW00094765598 ftApr 27May 9May 24Oct 6
BerlinBerlin, USC00270690920 ftApr 30May 14May 30Sep 30
KeeneKeene, USC00274399511 ftApr 30May 14May 28Oct 1
Crop chart

When to start seeds in New Hampshire, spring 2027

Counted back from the median last frost at Concord, May 8. Pick another station to redraw the chart for it.

Seed starting calendar for Concord, New Hampshire, spring 2027JanFebMarAprMayOnion (from seed)Onion (from seed): start indoors Jan 30 to Feb 13Onion (from seed): harden off Mar 27 to Apr 10Onion (from seed): set out Apr 10 to Apr 17PepperPepper: start indoors Mar 13 to Mar 27Pepper: harden off May 8 to May 22Pepper: set out May 22 to May 29EggplantEggplant: start indoors Mar 13 to Mar 27Eggplant: harden off May 8 to May 22Eggplant: set out May 22 to May 29TomatoTomato: start indoors Mar 20 to Apr 3Tomato: harden off May 1 to May 15Tomato: set out May 15 to May 22BroccoliBroccoli: start indoors Feb 27 to Mar 13Broccoli: harden off Mar 27 to Apr 10Broccoli: set out Apr 10 to Apr 24CabbageCabbage: start indoors Feb 27 to Mar 13Cabbage: harden off Mar 27 to Apr 10Cabbage: set out Apr 10 to Apr 17LettuceLettuce: start indoors Mar 6 to Mar 13Lettuce: harden off Mar 27 to Apr 10Lettuce: set out Apr 10 to Apr 17BasilBasil: start indoors Mar 27 to Apr 10Basil: harden off May 8 to May 22Basil: set out May 22 to May 29CucumberCucumber: start indoors Apr 17 to Apr 24Cucumber: harden off May 1 to May 15Cucumber: set out May 15 to May 22Cucumber: sow outdoors May 8 to May 15Summer squashSummer squash: start indoors Apr 24 to May 1Summer squash: harden off May 8 to May 22Summer squash: set out May 22 to May 29Summer squash: sow outdoors May 8 to May 15PeasPeas: sow outdoors Apr 10 to Apr 24CarrotCarrot: sow outdoors Apr 24 to May 8BeansBeans: sow outdoors May 8 to May 15Sweet cornSweet corn: sow outdoors May 8 to May 15Median last frost May 89 in 10 years May 22
Start indoorsHarden offSet outSow outdoorsMedian last frostLast freeze passed in 9 of 10 years
Every crop, counted from a median last frost of May 8
CropStart indoorsSet outSow outdoorsFrost class
TomatoMar 20 to Apr 3May 15 to May 22Tender, very tender
PepperMar 13 to Mar 27May 22 to May 29Tender, very tender
EggplantMar 13 to Mar 27May 22 to May 29Tender, very tender
BasilMar 27 to Apr 10May 22 to May 29Tender
CeleryFeb 13 to Feb 27May 8 to May 15Tender
CucumberApr 17 to Apr 24May 15 to May 22May 8 to May 15Tender
Summer squashApr 24 to May 1May 22 to May 29May 8 to May 15Tender
Winter squashApr 24 to May 1May 22 to May 29May 22 to May 29Tender, very tender
PumpkinApr 24 to May 1May 22 to May 29May 22 to May 29Tender, very tender
Melon (cantaloupe)Apr 24 to May 1May 22 to May 29Tender, very tender
WatermelonApr 17 to May 1May 22 to May 29Tender, very tender
Onion (from seed)Jan 30 to Feb 13Apr 10 to Apr 17Hardy
LeekJan 30 to Feb 13Apr 10 to Apr 17Hardy
ParsleyFeb 6 to Feb 13Apr 17 to Apr 24Half-hardy
BroccoliFeb 27 to Mar 13Apr 10 to Apr 24Hardy
Brussels sproutsFeb 27 to Mar 13Apr 10 to Apr 24Hardy
CabbageFeb 27 to Mar 13Apr 10 to Apr 17Hardy
CauliflowerMar 13 to Mar 27Apr 24 to May 1Half-hardy
KaleFeb 27 to Mar 13Apr 10 to Apr 17Hardy
LettuceMar 6 to Mar 13Apr 10 to Apr 17Hardy
Swiss chardMar 13 to Mar 27Apr 24 to May 1Apr 10 to Apr 17Half-hardy
SpinachFeb 13 to Feb 27Mar 27 to Apr 17Apr 10 to Apr 24Hardy
PeasApr 10 to Apr 24Hardy
RadishApr 10 to Apr 24Hardy
CarrotApr 24 to May 8Half-hardy
BeetApr 24 to May 8Half-hardy
BeansMay 8 to May 15Tender
Sweet cornMay 8 to May 15Tender
Six square pots of dark compost seen from above, each holding a single seedling with two narrow seed leaves
Tomato seedlings at the seed leaf stage, one to a pot. The University of Minnesota Extension holds off on fertilizer until a seedling has several sets of true leaves, then feeds at quarter strength once a week. “Tomato Seedlings (49768696597)” by Amanda Slater from Coventry, West Midlands, UK, CC BY-SA 2.0
Extension guide

What University of New Hampshire Cooperative Extension advises

University of New Hampshire Cooperative Extension publishes the planting guide New Hampshire gardeners work from, Growing Vegetables: When to Plant Your Vegetable Garden [fact sheet].

“Using a calendar, mark the date and count backwards the number of weeks the seed takes to grow from sowing. This will be the date you will start your seeds.”
University of New Hampshire Cooperative Extension, Growing Vegetables: When to Plant Your Vegetable Garden [fact sheet], quoted exactly.
“This period may range from four to 12 weeks before transplanting, depending upon the speed of germination, the rate of growth, and the cultural conditions provided.”
University of New Hampshire Cooperative Extension, Starting Plants From Seed [fact sheet], quoted exactly.
A gardener kneeling beside a raised bed setting a young tomato plant into dark soil, an empty nursery pot beside her
Setting out a tomato in June at a community garden. Tender crops go out after the last frost, and after a week or two of hardening off outdoors. “Volunteer planting heirloom tomato (4704185147)”, Pacific Southwest Region 5, Public domain

Seed starting questions for New Hampshire

Frost dates from NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal, by station (v1.0.1). Planting guidance from University of New Hampshire Cooperative Extension, quoted exactly. Seed starting weeks from UNH Cooperative Extension. Compiled 2026-09-21.

First frost in New HampshireThe other end of the season: when fall frost ends the tender crops.Soil temperatureBeans, corn and squash sown direct wait on warm soil as well as the last frost.New Hampshire lawn care calendarSpring seeding, feeding and mowing dates on the same climate.Fall planting calendarGarlic, cool season crops and a second sowing window in the fall.Frost dates by ZIPFirst and last frost odds for any address.

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