When to Plant in North Dakota: Vegetable & Flower Planting Calendar
Quick answer
Plant around your local last spring frost: across the 388 North Dakota ZIP codes where frost comes in most years, the median is May 12 and the median first fall frost is Sep 28 (nearest NOAA station, 1991–2020). Transplant tomatoes 1–2 weeks after your last frost: Zone 3 areas: May 24 – May 31; Zone 4 areas: May 19 – May 26.
North Dakota spans USDA hardiness zones 3b–4b on the 2023 USDA map (by ZIP code, via PRISM). For the 388 of its 388 ZIP codes where frost comes in most years, the nearest NOAA station’s median last spring frost (32°F, 1991–2020) is May 12 (middle 80% of ZIP codes: May 6 – May 19) and the median first fall frost is Sep 28 (Sep 22 – Oct 3). 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).
North Dakota 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 3 (54 ZIP codes) | Langdon Exp Farm, ND, Edmore 4Nw, ND, Rolette 3Se, ND | May 17middle 80%: May 14 – May 21 | Sep 23middle 80%: Sep 20 – Sep 26 |
| Zone 4 (332 ZIP codes) | Casselton Agronomy Farm, ND, Petersburg 2 N, ND, Grafton, ND | May 12middle 80%: May 4 – May 18 | Sep 28middle 80%: Sep 23 – Oct 3 |
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 North Dakota 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 (Baker Muni Airport, MT, Breckenridge 3E, MN, Carlyle 13 Nw, MT, Georgetown 1 E, MN, Mc Laughlin, SD, Pollock, SD…). For your own ZIP, use the planner.
North Dakota vegetable planting calendar
Planting dates for each zone area of North Dakota, 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 3 areasLast frost May 17 · First frost Sep 23 | Zone 4 areasLast frost May 12 · First frost Sep 28 |
|---|---|---|
| Broccoli · Start indoors8–10 weeks before last frost | Mar 8 – Mar 22 | Mar 3 – Mar 17 |
| Cabbage · Start indoors8–10 weeks before last frost | Mar 8 – Mar 22 | Mar 3 – Mar 17 |
| Kale · Start indoors8–10 weeks before last frost | Mar 8 – Mar 22 | Mar 3 – Mar 17 |
| Tomatoes · Start indoors6–8 weeks before last frost | Mar 22 – Apr 5 | Mar 17 – Mar 31 |
| Peppers · Start indoors6–8 weeks before last frost | Mar 22 – Apr 5 | Mar 17 – Mar 31 |
| Eggplant · Start indoors6–8 weeks before last frost | Mar 22 – Apr 5 | Mar 17 – Mar 31 |
| Peas · Direct sow4–6 weeks before last frost | Apr 5 – Apr 19Harvest (est.) Jun 4 – Jul 8 | Mar 31 – Apr 14Harvest (est.) May 30 – Jul 3 |
| Spinach · Direct sow4–6 weeks before last frost | Apr 5 – Apr 19Harvest (est.) May 20 – Jun 18 | Mar 31 – Apr 14Harvest (est.) May 15 – Jun 13 |
| Basil · Start indoors4–6 weeks before last frost | Apr 5 – Apr 19 | Mar 31 – Apr 14 |
| Radishes · Direct sow2–5 weeks before last frost | Apr 12 – May 3Harvest (est.) May 2 – Jun 2 | Apr 7 – Apr 28Harvest (est.) Apr 27 – May 28 |
| Lettuce · Direct sow2–4 weeks before last frost | Apr 19 – May 3Harvest (est.) Jun 18 – Jul 22 | Apr 14 – Apr 28Harvest (est.) Jun 13 – Jul 17 |
| Onions (sets/transplants) · Plant sets/transplants2–4 weeks before last frost | Apr 19 – May 3Harvest (est.) Jul 13 – Aug 31 | Apr 14 – Apr 28Harvest (est.) Jul 8 – Aug 26 |
| Broccoli · Transplant2–4 weeks before last frost | Apr 19 – May 3Harvest (est.) Jun 8 – Jul 12 | Apr 14 – Apr 28Harvest (est.) Jun 3 – Jul 7 |
| Cabbage · Transplant2–4 weeks before last frost | Apr 19 – May 3Harvest (est.) Jun 28 – Aug 1 | Apr 14 – Apr 28Harvest (est.) Jun 23 – Jul 27 |
| Kale · Transplant2–4 weeks before last frost | Apr 19 – May 3 | Apr 14 – Apr 28 |
| Marigolds · Start indoors0–3 weeks before last frost (3–4 weeks before setting out; Univ. of Idaho) | Apr 26 – May 17 | Apr 21 – May 12 |
| Zinnias · Start indoors0–3 weeks before last frost (3–4 weeks before setting out; Univ. of Idaho) | Apr 26 – May 17 | Apr 21 – May 12 |
| Potatoes · Plant seed potatoes1–2 weeks before last frost | May 3 – May 10Harvest (est.) Jul 27 – Aug 28 | Apr 28 – May 5Harvest (est.) Jul 22 – Aug 23 |
| Marigolds · Direct sow / transplantfrom the last frost to 2 weeks after (Univ. of Idaho) | May 17 – May 31 | May 12 – May 26 |
| Zinnias · Direct sow / transplantfrom the last frost to 2 weeks after (Univ. of Idaho) | May 17 – May 31 | May 12 – May 26 |
| Tomatoes · Transplant1–2 weeks after last frost | May 24 – May 31Harvest (est.) Aug 2 – Aug 29 | May 19 – May 26Harvest (est.) Jul 28 – Aug 24 |
| Beans (bush & pole) · Direct sow1–2 weeks after last frost | May 24 – May 31Harvest (est.) Jul 8 – Aug 9 | May 19 – May 26Harvest (est.) Jul 3 – Aug 4 |
| Sweet corn · Direct sow1–2 weeks after last frost | May 24 – May 31Harvest (est.) Jul 28 – Aug 29 | May 19 – May 26Harvest (est.) Jul 23 – Aug 24 |
| Cucumbers · Direct sow1–2 weeks after last frost | May 24 – May 31Harvest (est.) Jul 3 – Aug 4 | May 19 – May 26Harvest (est.) Jun 28 – Jul 30 |
| Squash · Direct sow1–2 weeks after last frost | May 24 – May 31Harvest (est.) Jul 3 – Jul 20 | May 19 – May 26Harvest (est.) Jun 28 – Jul 15 |
| Pumpkins · Direct sow1–3 weeks after last frost | May 24 – Jun 7Harvest (est.) Aug 12 – Sep 15 | May 19 – Jun 2Harvest (est.) Aug 7 – Sep 10 |
| Basil · Transplant1–2 weeks after last frost | May 24 – May 31Harvest (est.) Jul 5 – Jul 12 | May 19 – May 26Harvest (est.) Jun 30 – Jul 7 |
| Peppers · Transplant2–3 weeks after last frost | May 31 – Jun 7Harvest (est.) Aug 4 – Aug 21 | May 26 – Jun 2Harvest (est.) Jul 30 – Aug 16 |
| Eggplant · Transplant2–3 weeks after last frost | May 31 – Jun 7Harvest (est.) Aug 9 – Sep 5 | May 26 – Jun 2Harvest (est.) Aug 4 – Aug 31 |
| Broccoli · Fall transplant10–12 weeks before first fall frost | Jul 1 – Jul 15Harvest (est.) Aug 20 – Sep 23 | Jul 6 – Jul 20Harvest (est.) Aug 25 – Sep 28 |
| Cabbage · Fall transplant10–12 weeks before first fall frost | Jul 1 – Jul 15Harvest (est.) Sep 9 – Oct 13 | Jul 6 – Jul 20Harvest (est.) Sep 14 – Oct 18 |
| Kale · Fall sow8–10 weeks before first fall frost | Jul 15 – Jul 29Harvest (est.) Sep 3 – Oct 7 | Jul 20 – Aug 3Harvest (est.) Sep 8 – Oct 12 |
| Lettuce · Fall sow6–8 weeks before first fall frost | Jul 29 – Aug 12Harvest (est.) Sep 27 – Oct 31 | Aug 3 – Aug 17Harvest (est.) Oct 2 – Nov 5 |
| Spinach · Fall sow4–7 weeks before first fall frost (Virginia Tech) | Aug 5 – Aug 26Harvest (est.) Sep 19 – Oct 25 | Aug 10 – Aug 31Harvest (est.) Sep 24 – Oct 30 |
| Radishes · Fall sow4–6 weeks before first fall frost | Aug 12 – Aug 26Harvest (est.) Sep 1 – Sep 25 | Aug 17 – Aug 31Harvest (est.) Sep 6 – Sep 30 |
| 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 | Aug 31 – Oct 12 |
| 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 14 – Oct 26 |
| 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 14 – Oct 19Harvest (est.) May 22, 2027 – Jul 16, 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
North Dakota USDA zone guides: Zone 3 planting guide Zone 4 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 North Dakota 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 North Dakota?
Across the 388 North Dakota ZIP codes where frost comes in most years, the median last spring frost (32°F, NOAA 1991–2020) at the nearest station is May 12, and the middle 80% of ZIP codes range from May 6 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 North Dakota?
Transplant tomatoes outdoors 1–2 weeks after your average last frost, once nights stay above about 52°F (Colorado State). Typical dates: Zone 3 areas: May 24 – May 31; Zone 4 areas: May 19 – May 26.
What USDA zone is North Dakota?
North Dakota spans roughly USDA hardiness zones 3b–4b 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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