Dickinson, ND planting zone & frost dates
Dickinson is in USDA hardiness zone 4a. The last spring frost usually comes around May 20 and the first fall frost around September 22, for a growing season of about 123 days.
Planting calendar for Dickinson
Dates are counted from the average last spring frost (May 20) 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: Mar 25 – Apr 8 Transplant outdoors: May 27 – Jun 3 |
| Peppers | Start seeds indoors: Mar 11 – Mar 25 Transplant outdoors: Jun 3 – Jun 10 |
| Eggplant | Start seeds indoors: Mar 11 – Mar 25 Transplant outdoors: Jun 3 – Jun 10 |
| Broccoli | Start seeds indoors: Mar 11 – Mar 25 Transplant outdoors: Apr 22 – May 6 |
| Cabbage | Start seeds indoors: Mar 11 – Mar 25 Transplant outdoors: Apr 22 – May 6 |
| Onions (sets) | Plant outdoors: Apr 22 – May 6 |
| Peas | Sow outdoors: Apr 8 – Apr 22 |
| Spinach | Sow outdoors: Apr 8 – Apr 22 |
| Lettuce | Sow outdoors: Apr 22 – May 6 |
| Carrots | Sow outdoors: Apr 22 – May 6 |
| Potatoes | Plant outdoors: Apr 22 – May 6 |
| Beans | Sow outdoors: May 27 – Jun 3 |
| Sweet corn | Sow outdoors: May 27 – Jun 3 |
| Cucumbers | Sow outdoors: May 27 – Jun 3 |
| Squash & zucchini | Sow outdoors: May 27 – Jun 3 |
| Basil | Start seeds indoors: Apr 8 – Apr 22 Transplant outdoors: May 27 – Jun 3 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Jul 28 (8 weeks before the average first fall frost on Sep 22).
Useful for zone 4a 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
- Cold frame / mini greenhouse — adds weeks to a short season
As an Amazon Associate, FrostZoneMap earns from qualifying purchases, at no extra cost to you.
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | May 8 | May 20 | Jun 1 |
| First 32°F frost in fall is before | Oct 3 | Sep 22 | Sep 8 |
How to read it: in spring there is a 10% chance of a frost after June 1, so that is a safe date for tender plants. In fall there is a 10% chance of frost before September 8. A hard freeze (28°F) usually ends around May 10.
Hardiness zone by ZIP code in Dickinson
- 58601 zone 4b
- 58602 zone 4a
Nearby cities
- Williston zone 4a, last frost May 21
- Mandan zone 4a, last frost May 13
- Bismarck zone 4a, last frost May 10
- Minot zone 4a, last frost May 10
- Jamestown zone 4b, last frost May 8
- Grand Forks zone 4a, last frost May 10
- West Fargo zone 4a, last frost May 10
- Fargo zone 4a, last frost May 5
Questions
What growing zone is Dickinson, ND?
Dickinson is in USDA Plant Hardiness Zone 4a (average extreme winter low -30°F to -25°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 4b.
When is the last frost in Dickinson?
The average last spring frost (32°F) in Dickinson is May 20. There is still a 10% chance of frost until June 1.
When can I plant tomatoes in Dickinson?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 27 – Jun 3. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Dickinson, ND (USC00322188), 1.6 km (1.0 mi) from the city center, elevation 750 m, based on 21 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.