When to Plant in New Hampshire: Vegetable & Flower Planting Calendar
Quick answer
Plant around your local last spring frost: across the 247 New Hampshire ZIP codes where frost comes in most years, the median is May 7 and the median first fall frost is Oct 4 (nearest NOAA station, 1991–2020). Transplant tomatoes 1–2 weeks after your last frost: Zone 4 areas: May 29 – Jun 5; Zone 5 areas: May 19 – May 26; Zone 6 areas: May 10 – May 17.
New Hampshire spans USDA hardiness zones 4a–6b on the 2023 USDA map (by ZIP code, via PRISM). For the 247 of its 247 ZIP codes where frost comes in most years, the nearest NOAA station’s median last spring frost (32°F, 1991–2020) is May 7 (middle 80% of ZIP codes: Apr 30 – May 19) and the median first fall frost is Oct 4 (Sep 26 – Oct 12). Use this guide to time seed-starting, transplanting and fall planting.
Where these dates come from: every date range is counted from the median (50% probability) 32°F last spring and first fall frost dates in NOAA’s 1991–2020 U.S. Climate Normals for the area shown. The rule under each date, such as “4–6 weeks before last frost,” shows how it was counted. These are averages: in about half of years a frost still comes after the spring date, and elevation, nearby water and microclimate can shift your yard by a week or more. For dates for your exact location, enter your ZIP code in the planner.
How we count planting dates: the weeks before or after frost for each crop come from university extension planting guides: UNH Extension, When to Plant Your Vegetable Garden; Rutgers FS787, Starting Vegetable Seeds Indoors; Virginia Tech 426-331, Home Garden Vegetable Planting Guide; University of Maryland Extension, Vegetable Planting Calendar; and University of Idaho CIS 1209 (marigolds and zinnias). Bulb windows approximate Rutgers’ rule to plant when soil falls below 60°F (FS1220), and garlic follows SDSU, Illinois and Virginia Tech. Temperature notes: UMD (potatoes), UMN (sweet corn), UC ANR (peppers, hardening off), UMN (eggplant), Colorado State (tomatoes) and SDSU (hardening off).
New Hampshire frost dates by zone area
| Zone areas | Most common nearest NOAA stations | Median last spring frost (32°F) | Median first fall frost (32°F) |
|---|---|---|---|
| Zone 4 (14 ZIP codes) | N Stratford, NH, Whitefield Mt Washington Airport, NH, Bethlehem 2, NH | May 22middle 80%: May 13 – May 30 | Sep 23middle 80%: Sep 19 – Oct 1 |
| Zone 5 (129 ZIP codes) | Lakeport 2, NH, Tamworth 4, NH, Benton 5 Sw, NH | May 12middle 80%: Apr 30 – May 20 | Oct 2middle 80%: Sep 26 – Oct 16 |
| Zone 6 (104 ZIP codes) | Greenland, NH, W Hampstead, NH, Massabesic Lake, NH | May 3middle 80%: Apr 30 – May 10 | Oct 8middle 80%: Oct 3 – Oct 12 |
Source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991–2020, annual/seasonal freeze-date probabilities (32°F, 50% probability). Station-level medians; your yard may differ.
How this table is built: each New Hampshire ZIP code is matched to its nearest NOAA 1991–2020 freeze-data station (within 60 miles) and grouped by its 2023 USDA hardiness zone; dates are medians across the ZIP codes in each group. Some nearest stations are across the state line (Fryeburg E Slopes Airport, ME, Haverhill, MA, Lawrence, MA, N Hartland Lake, VT, N Springfield Lake, VT, Saint Johnsbury, VT…). For your own ZIP, use the planner.
New Hampshire vegetable planting calendar
Planting dates for each zone area of New Hampshire, counted from that area’s median frost dates (shown under each column). Rows run in calendar order. For your exact dates, enter your ZIP.
| Plant, task and rule | Zone 4 areasLast frost May 22 · First frost Sep 23 | Zone 5 areasLast frost May 12 · First frost Oct 2 | Zone 6 areasLast frost May 3 · First frost Oct 8 |
|---|---|---|---|
| Broccoli · Start indoors8–10 weeks before last frost | Mar 13 – Mar 27 | Mar 3 – Mar 17 | Feb 22 – Mar 8 |
| Cabbage · Start indoors8–10 weeks before last frost | Mar 13 – Mar 27 | Mar 3 – Mar 17 | Feb 22 – Mar 8 |
| Kale · Start indoors8–10 weeks before last frost | Mar 13 – Mar 27 | Mar 3 – Mar 17 | Feb 22 – Mar 8 |
| Tomatoes · Start indoors6–8 weeks before last frost | Mar 27 – Apr 10 | Mar 17 – Mar 31 | Mar 8 – Mar 22 |
| Peppers · Start indoors6–8 weeks before last frost | Mar 27 – Apr 10 | Mar 17 – Mar 31 | Mar 8 – Mar 22 |
| Eggplant · Start indoors6–8 weeks before last frost | Mar 27 – Apr 10 | Mar 17 – Mar 31 | Mar 8 – Mar 22 |
| Peas · Direct sow4–6 weeks before last frost | Apr 10 – Apr 24Harvest (est.) Jun 9 – Jul 13 | Mar 31 – Apr 14Harvest (est.) May 30 – Jul 3 | Mar 22 – Apr 5Harvest (est.) May 21 – Jun 24 |
| Spinach · Direct sow4–6 weeks before last frost | Apr 10 – Apr 24Harvest (est.) May 25 – Jun 23 | Mar 31 – Apr 14Harvest (est.) May 15 – Jun 13 | Mar 22 – Apr 5Harvest (est.) May 6 – Jun 4 |
| Basil · Start indoors4–6 weeks before last frost | Apr 10 – Apr 24 | Mar 31 – Apr 14 | Mar 22 – Apr 5 |
| Radishes · Direct sow2–5 weeks before last frost | Apr 17 – May 8Harvest (est.) May 7 – Jun 7 | Apr 7 – Apr 28Harvest (est.) Apr 27 – May 28 | Mar 29 – Apr 19Harvest (est.) Apr 18 – May 19 |
| Lettuce · Direct sow2–4 weeks before last frost | Apr 24 – May 8Harvest (est.) Jun 23 – Jul 27 | Apr 14 – Apr 28Harvest (est.) Jun 13 – Jul 17 | Apr 5 – Apr 19Harvest (est.) Jun 4 – Jul 8 |
| Onions (sets/transplants) · Plant sets/transplants2–4 weeks before last frost | Apr 24 – May 8Harvest (est.) Jul 18 – Sep 5 | Apr 14 – Apr 28Harvest (est.) Jul 8 – Aug 26 | Apr 5 – Apr 19Harvest (est.) Jun 29 – Aug 17 |
| Broccoli · Transplant2–4 weeks before last frost | Apr 24 – May 8Harvest (est.) Jun 13 – Jul 17 | Apr 14 – Apr 28Harvest (est.) Jun 3 – Jul 7 | Apr 5 – Apr 19Harvest (est.) May 25 – Jun 28 |
| Cabbage · Transplant2–4 weeks before last frost | Apr 24 – May 8Harvest (est.) Jul 3 – Aug 6 | Apr 14 – Apr 28Harvest (est.) Jun 23 – Jul 27 | Apr 5 – Apr 19Harvest (est.) Jun 14 – Jul 18 |
| Kale · Transplant2–4 weeks before last frost | Apr 24 – May 8 | Apr 14 – Apr 28 | Apr 5 – Apr 19 |
| Marigolds · Start indoors0–3 weeks before last frost (3–4 weeks before setting out; Univ. of Idaho) | May 1 – May 22 | Apr 21 – May 12 | Apr 12 – May 3 |
| Zinnias · Start indoors0–3 weeks before last frost (3–4 weeks before setting out; Univ. of Idaho) | May 1 – May 22 | Apr 21 – May 12 | Apr 12 – May 3 |
| Potatoes · Plant seed potatoes1–2 weeks before last frost | May 8 – May 15Harvest (est.) Aug 1 – Sep 2 | Apr 28 – May 5Harvest (est.) Jul 22 – Aug 23 | Apr 19 – Apr 26Harvest (est.) Jul 13 – Aug 14 |
| Marigolds · Direct sow / transplantfrom the last frost to 2 weeks after (Univ. of Idaho) | May 22 – Jun 5 | May 12 – May 26 | May 3 – May 17 |
| Zinnias · Direct sow / transplantfrom the last frost to 2 weeks after (Univ. of Idaho) | May 22 – Jun 5 | May 12 – May 26 | May 3 – May 17 |
| Tomatoes · Transplant1–2 weeks after last frost | May 29 – Jun 5Harvest (est.) Aug 7 – Sep 3 | May 19 – May 26Harvest (est.) Jul 28 – Aug 24 | May 10 – May 17Harvest (est.) Jul 19 – Aug 15 |
| Beans (bush & pole) · Direct sow1–2 weeks after last frost | May 29 – Jun 5Harvest (est.) Jul 13 – Aug 14 | May 19 – May 26Harvest (est.) Jul 3 – Aug 4 | May 10 – May 17Harvest (est.) Jun 24 – Jul 26 |
| Sweet corn · Direct sow1–2 weeks after last frost | May 29 – Jun 5Harvest (est.) Aug 2 – Sep 3 | May 19 – May 26Harvest (est.) Jul 23 – Aug 24 | May 10 – May 17Harvest (est.) Jul 14 – Aug 15 |
| Cucumbers · Direct sow1–2 weeks after last frost | May 29 – Jun 5Harvest (est.) Jul 8 – Aug 9 | May 19 – May 26Harvest (est.) Jun 28 – Jul 30 | May 10 – May 17Harvest (est.) Jun 19 – Jul 21 |
| Squash · Direct sow1–2 weeks after last frost | May 29 – Jun 5Harvest (est.) Jul 8 – Jul 25 | May 19 – May 26Harvest (est.) Jun 28 – Jul 15 | May 10 – May 17Harvest (est.) Jun 19 – Jul 6 |
| Pumpkins · Direct sow1–3 weeks after last frost | May 29 – Jun 12Harvest (est.) Aug 17 – Sep 20 | May 19 – Jun 2Harvest (est.) Aug 7 – Sep 10 | May 10 – May 24Harvest (est.) Jul 29 – Sep 1 |
| Basil · Transplant1–2 weeks after last frost | May 29 – Jun 5Harvest (est.) Jul 10 – Jul 17 | May 19 – May 26Harvest (est.) Jun 30 – Jul 7 | May 10 – May 17Harvest (est.) Jun 21 – Jun 28 |
| Peppers · Transplant2–3 weeks after last frost | Jun 5 – Jun 12Harvest (est.) Aug 9 – Aug 26 | May 26 – Jun 2Harvest (est.) Jul 30 – Aug 16 | May 17 – May 24Harvest (est.) Jul 21 – Aug 7 |
| Eggplant · Transplant2–3 weeks after last frost | Jun 5 – Jun 12Harvest (est.) Aug 14 – Sep 10 | May 26 – Jun 2Harvest (est.) Aug 4 – Aug 31 | May 17 – May 24Harvest (est.) Jul 26 – Aug 22 |
| Broccoli · Fall transplant10–12 weeks before first fall frost | Jul 1 – Jul 15Harvest (est.) Aug 20 – Sep 23 | Jul 10 – Jul 24Harvest (est.) Aug 29 – Oct 2 | Jul 16 – Jul 30Harvest (est.) Sep 4 – Oct 8 |
| Cabbage · Fall transplant10–12 weeks before first fall frost | Jul 1 – Jul 15Harvest (est.) Sep 9 – Oct 13 | Jul 10 – Jul 24Harvest (est.) Sep 18 – Oct 22 | Jul 16 – Jul 30Harvest (est.) Sep 24 – Oct 28 |
| Kale · Fall sow8–10 weeks before first fall frost | Jul 15 – Jul 29Harvest (est.) Sep 3 – Oct 7 | Jul 24 – Aug 7Harvest (est.) Sep 12 – Oct 16 | Jul 30 – Aug 13Harvest (est.) Sep 18 – Oct 22 |
| Lettuce · Fall sow6–8 weeks before first fall frost | Jul 29 – Aug 12Harvest (est.) Sep 27 – Oct 31 | Aug 7 – Aug 21Harvest (est.) Oct 6 – Nov 9 | Aug 13 – Aug 27Harvest (est.) Oct 12 – Nov 15 |
| Spinach · Fall sow4–7 weeks before first fall frost (Virginia Tech) | Aug 5 – Aug 26Harvest (est.) Sep 19 – Oct 25 | Aug 14 – Sep 4Harvest (est.) Sep 28 – Nov 3 | Aug 20 – Sep 10Harvest (est.) Oct 4 – Nov 9 |
| Radishes · Fall sow4–6 weeks before first fall frost | Aug 12 – Aug 26Harvest (est.) Sep 1 – Sep 25 | Aug 21 – Sep 4Harvest (est.) Sep 10 – Oct 4 | Aug 27 – Sep 10Harvest (est.) Sep 16 – Oct 10 |
| Daffodils · Fall plant bulbs4 weeks before to 2 weeks after first fall frost (our approximation of when soil falls below 60°F; Rutgers) | Aug 26 – Oct 7 | Sep 4 – Oct 16 | Sep 10 – Oct 22 |
| Tulips · Fall plant bulbs2 weeks before to 4 weeks after first fall frost (our approximation of when soil falls below 60°F; Rutgers) | Sep 9 – Oct 21 | Sep 18 – Oct 30 | Sep 24 – Nov 5 |
| Garlic · Fall plant cloves2 weeks before to 3 weeks after first fall frost, while the soil is still workable (SDSU, Illinois, Virginia Tech) | Sep 9 – Oct 14Harvest (est.) May 17, 2027 – Jul 11, 2027 | Sep 18 – Oct 23Harvest (est.) May 26, 2027 – Jul 20, 2027 | Sep 24 – Oct 29Harvest (est.) Jun 1, 2027 – Jul 26, 2027 |
About the harvest estimates
Each expected harvest window adds the days to harvest from the sources below to the planting window. Days count from sowing seed (or planting seed potatoes, onion sets or garlic cloves) or, where marked, from setting transplants out; “Start indoors” rows have no harvest of their own. Harvest timing varies with variety and weather, and many crops keep producing for weeks after the first picking. For frost-tender crops (tomatoes, peppers, eggplant, beans, sweet corn, cucumbers, squash, pumpkins, basil) the window stops at the first fall frost: harvest may end early at the first fall frost. Flowers and bulbs show no harvest window, and kale has no sourced figure for spring transplants.
Sources: UF/IFAS Extension, Florida Vegetable Gardening Guide (SP103/VH021), Table 1, “Days to Harvest”; University of Maryland Extension, Growing Onions in a Home Garden; University of Maryland Extension, Growing Garlic in a Home Garden; University of Maryland Extension, Growing Basil in a Home Garden.
Growing notes for each crop
- Peas: Tolerates light frost; sow when soil is workable
- Spinach: Fall crop too: sow 4–7 weeks before first fall frost (Virginia Tech)
- Lettuce: Bolts in heat; succession sow; fall crop too
- Radishes: Fast (3–4 weeks); sow again for fall (see Fall sow dates)
- Kale: Fall crop too (see Fall sow dates); frost sweetens leaves
- Onions (sets/transplants): Choose day-length type suited to your latitude
- Potatoes: Soil at least 45°F (UMD); hill as plants grow
- Broccoli: Cool-season; harden off; good fall crop
- Cabbage: Cool-season; harden off; good fall crop
- Tomatoes: Wait for nights reliably above about 52°F (Colorado State)
- Peppers: Need warm soil: about 65°F is optimal for transplanting (UC ANR)
- Eggplant: Transplant after nights stay above 50°F (UMN)
- Beans (bush & pole): Seeds rot in cold, wet soil
- Sweet corn: Soil 60°F+ (UNH, UMN); plant in blocks for pollination
- Cucumbers: Frost-tender; watch for cucumber beetles
- Squash: Frost-tender; watch for squash vine borer
- Pumpkins: For October pumpkins, many sow in late May–June
- Basil: Very cold-sensitive
- Marigolds: Easy warm-season annual
- Zinnias: Easy warm-season annual
- Tulips: Our frost-date window is an approximation of that soil rule. In zone 9, chill bulbs 12–16 weeks first (Clemson)
- Daffodils: Our frost-date window is an approximation of that soil rule; slightly earlier than tulips is fine
- Garlic: Harvest the following early summer
New Hampshire USDA zone guides: Zone 4 planting guide Zone 5 planting guide Zone 6 planting guide
How we count planting dates: the weeks before or after frost for each crop come from university extension planting guides: UNH Extension, When to Plant Your Vegetable Garden; Rutgers FS787, Starting Vegetable Seeds Indoors; Virginia Tech 426-331, Home Garden Vegetable Planting Guide; University of Maryland Extension, Vegetable Planting Calendar; and University of Idaho CIS 1209 (marigolds and zinnias). Bulb windows approximate Rutgers’ rule to plant when soil falls below 60°F (FS1220), and garlic follows SDSU, Illinois and Virginia Tech. Temperature notes: UMD (potatoes), UMN (sweet corn), UC ANR (peppers, hardening off), UMN (eggplant), Colorado State (tomatoes) and SDSU (hardening off).
Tips for New Hampshire gardeners
- Watch soil temperature, not just the calendar — warm-season crops stall in cold soil. An inexpensive soil thermometer helps.
- Harden off transplants over 7–10 days before planting out (UC ANR, SDSU).
- Ask your local Cooperative Extension office about varieties and timing for your county; find it in the USDA NIFA land-grant university directory.
- Keep weeds down early — see our weed identification guide.
Frequently asked questions
When is the last frost in New Hampshire?
Across the 247 New Hampshire ZIP codes where frost comes in most years, the median last spring frost (32°F, NOAA 1991–2020) at the nearest station is May 7, and the middle 80% of ZIP codes range from Apr 30 to May 19. Check the average for your ZIP code, and remember frost can occur after the average date.
When can I plant tomatoes in New Hampshire?
Transplant tomatoes outdoors 1–2 weeks after your average last frost, once nights stay above about 52°F (Colorado State). Typical dates: Zone 4 areas: May 29 – Jun 5; Zone 5 areas: May 19 – May 26; Zone 6 areas: May 10 – May 17.
What USDA zone is New Hampshire?
New Hampshire spans roughly USDA hardiness zones 4a–6b on the 2023 USDA map (by ZIP code, via PRISM). Hardiness zones describe winter low temperatures, not frost dates.
Other state planting calendars
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