Grasston, MN frost dates
How Grasston compares
- In 8 years out of 10, the last spring frost in Grasston falls between May 3 and May 30, a 27-day window. The first fall frost falls between September 9 and October 6.
- The median last frost is 11 days later than the Minnesota median of May 5.
- Its 131-day growing season is longer than 8% of the 801 Minnesota places with a regular frost season (state median 151 days).
- The last frost is 4 days later than the zone 4a median of May 12. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4a chart.
- The weather station records an average of 183 nights a year at or below 32°F.
- Compared with Saint Cloud, MN, 90 km away, the last frost here is 9 days later than there and the growing season is 15 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 3 |
| 50% (median) | May 16 |
| 10% (safe for tender plants) | May 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 9 |
| 50% (median) | September 24 |
| 90% (late) | October 6 |
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 Grasston, MN
Grasston, MN frost dates — last frost May 16, first frost Sep 24, zone 4a. whenisthelastfrost.com
When to plant vegetables in Grasston, MN
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 21 – Mar 7 | Apr 18 – May 2 | — | — |
| Peppers | Mar 7 – Mar 21 | May 30 – Jun 13 | — | — |
| Eggplant | Mar 7 – Mar 21 | May 30 – Jun 13 | — | — |
| Tomatoes | Mar 21 – Apr 4 | May 23 – Jun 6 | — | — |
| Lettuce | Mar 21 – Apr 4 | Apr 25 – May 9 | Apr 18 – May 23 | Jul 30 – Aug 27 |
| Kale | Mar 21 – Apr 4 | Apr 18 – May 2 | Apr 18 – May 2 | Jul 16 – Aug 6 |
| Broccoli | Mar 21 – Apr 4 | May 2 – May 16 | — | Jun 18 – Jul 9 |
| Cabbage | Mar 21 – Apr 4 | Apr 25 – May 9 | — | Jun 18 – Jul 9 |
| Cauliflower | Mar 21 – Apr 4 | May 2 – May 16 | — | Jun 18 – Jul 9 |
| Okra | Apr 4 – Apr 18 | Jun 6 – Jun 20 | Jun 6 – Jun 20 | — |
| Basil | Apr 4 – Apr 18 | May 23 – Jun 6 | — | — |
| Peas | — | — | Apr 4 – Apr 25 | Jul 2 – Jul 23 |
| Spinach | — | — | Apr 4 – Apr 25 | Jul 30 – Aug 20 |
| Radishes | — | — | Apr 11 – May 23 | Aug 13 – Sep 3 |
| Cucumbers | Apr 18 – Apr 25 | May 30 – Jun 6 | May 23 – Jun 6 | Jul 9 – Jul 23 |
| Zucchini & Summer Squash | Apr 18 – Apr 25 | — | May 23 – Jun 6 | Jul 16 – Jul 30 |
| Winter Squash & Pumpkins | Apr 18 – Apr 25 | — | May 23 – Jun 6 | — |
| Melons & Watermelon | Apr 18 – Apr 25 | May 30 – Jun 13 | — | — |
| Carrots | — | — | Apr 25 – May 23 | Jul 2 – Jul 16 |
| Beets | — | — | Apr 25 – May 23 | Jul 16 – Jul 30 |
| Potatoes | — | — | Apr 25 – May 16 | — |
| Swiss Chard | — | — | May 2 – May 30 | Jul 16 – Jul 30 |
| Cilantro | — | — | May 2 – May 23 | Jul 30 – Aug 20 |
| Green Beans | — | — | May 23 – Jun 13 | Jul 9 – Jul 23 |
| Sweet Corn | — | — | May 23 – Jun 6 | — |
| Sweet Potatoes | — | May 30 – Jun 20 | — | — |
| Garlic | — | — | — | Sep 10 – Oct 15 |
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 Hinckley, MN weather station, 16 km away (elevation 1,037 ft (316 m)).
Frost dates near Grasston
- Henriette May 9 · Sep 30
- Brook Park May 16 · Sep 24
- Pine City May 11 · Oct 1
- Rock Creek May 11 · Oct 1
- Mora May 9 · Sep 30
- Braham May 2 · Oct 4
- Rush City May 11 · Oct 1
- Hinckley May 16 · Sep 24
- Stanchfield May 2 · Oct 4
- Grandy May 2 · Oct 4
Frequently asked questions
When is the last frost in Grasston, MN?
The median last spring frost in Grasston, MN is May 16. There is still about a 10% chance of frost after May 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Grasston, MN?
The median first fall frost is September 24, with about a 10% chance of frost before September 9.
How long is the growing season in Grasston, MN?
About 131 days between the median last spring frost and first fall frost.
What planting zone is Grasston, MN?
Grasston, MN is in USDA hardiness zone 4a.