Garrison, ND frost dates
How Garrison compares
- In 8 years out of 10, the last spring frost in Garrison falls between May 2 and May 28, a 26-day window. The first fall frost falls between September 13 and October 9.
- The median last frost is 2 days later than the North Dakota median of May 12.
- Its 135-day growing season is longer than 33% of the 372 North Dakota places with a regular frost season (state median 139 days).
- The last frost is typical for zone 4a, where the median is May 12.
- The weather station records an average of 186 nights a year at or below 32°F.
- Compared with Bismarck, ND, 115 km away, the last frost here is 4 days later than there and the growing season is 8 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 2 |
| 50% (median) | May 14 |
| 10% (safe for tender plants) | May 28 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 13 |
| 50% (median) | September 26 |
| 90% (late) | October 9 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Garrison, ND
Garrison, ND frost dates — last frost May 14, first frost Sep 26, zone 4a. whenisthelastfrost.com
When to plant vegetables in Garrison, ND
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 19 – Mar 5 | Apr 16 – Apr 30 | — | — |
| Peppers | Mar 5 – Mar 19 | May 28 – Jun 11 | — | — |
| Eggplant | Mar 5 – Mar 19 | May 28 – Jun 11 | — | — |
| Tomatoes | Mar 19 – Apr 2 | May 21 – Jun 4 | — | — |
| Lettuce | Mar 19 – Apr 2 | Apr 23 – May 7 | Apr 16 – May 21 | Aug 1 – Aug 29 |
| Kale | Mar 19 – Apr 2 | Apr 16 – Apr 30 | Apr 16 – Apr 30 | Jul 18 – Aug 8 |
| Broccoli | Mar 19 – Apr 2 | Apr 30 – May 14 | — | Jun 20 – Jul 11 |
| Cabbage | Mar 19 – Apr 2 | Apr 23 – May 7 | — | Jun 20 – Jul 11 |
| Cauliflower | Mar 19 – Apr 2 | Apr 30 – May 14 | — | Jun 20 – Jul 11 |
| Okra | Apr 2 – Apr 16 | Jun 4 – Jun 18 | Jun 4 – Jun 18 | — |
| Basil | Apr 2 – Apr 16 | May 21 – Jun 4 | — | — |
| Peas | — | — | Apr 2 – Apr 23 | Jul 4 – Jul 25 |
| Spinach | — | — | Apr 2 – Apr 23 | Aug 1 – Aug 22 |
| Radishes | — | — | Apr 9 – May 21 | Aug 15 – Sep 5 |
| Cucumbers | Apr 16 – Apr 23 | May 28 – Jun 4 | May 21 – Jun 4 | Jul 11 – Jul 25 |
| Zucchini & Summer Squash | Apr 16 – Apr 23 | — | May 21 – Jun 4 | Jul 18 – Aug 1 |
| Winter Squash & Pumpkins | Apr 16 – Apr 23 | — | May 21 – Jun 4 | — |
| Melons & Watermelon | Apr 16 – Apr 23 | May 28 – Jun 11 | — | — |
| Carrots | — | — | Apr 23 – May 21 | Jul 4 – Jul 18 |
| Beets | — | — | Apr 23 – May 21 | Jul 18 – Aug 1 |
| Potatoes | — | — | Apr 23 – May 14 | — |
| Swiss Chard | — | — | Apr 30 – May 28 | Jul 18 – Aug 1 |
| Cilantro | — | — | Apr 30 – May 21 | Aug 1 – Aug 22 |
| Green Beans | — | — | May 21 – Jun 11 | Jul 11 – Jul 25 |
| Sweet Corn | — | — | May 21 – Jun 4 | — |
| Sweet Potatoes | — | May 28 – Jun 18 | — | — |
| Garlic | — | — | — | Sep 12 – Oct 17 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Garrison, ND weather station, 13 km away (elevation 1,909 ft (582 m)).
Frost dates near Garrison
- Roseglen May 14 · Sep 26
- Douglas May 10 · Sep 28
- Riverdale May 12 · Oct 3
- Max May 10 · Sep 28
- Coleharbor May 10 · Sep 29
- Ryder May 10 · Sep 28
- Makoti May 10 · Sep 28
- Hazen May 21 · Sep 20
- Underwood May 10 · Sep 29
- Stanton May 12 · Oct 3
Frequently asked questions
When is the last frost in Garrison, ND?
The median last spring frost in Garrison, ND is May 14. There is still about a 10% chance of frost after May 28, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Garrison, ND?
The median first fall frost is September 26, with about a 10% chance of frost before September 13.
How long is the growing season in Garrison, ND?
About 135 days between the median last spring frost and first fall frost.
What planting zone is Garrison, ND?
Garrison, ND is in USDA hardiness zone 4a.