New Ulm, MN planting zone & frost dates
New Ulm is in USDA hardiness zone 5a. The last spring frost usually comes around April 29 and the first fall frost around October 7, for a growing season of about 161 days.
Planting calendar for New Ulm
Dates are counted from the average last spring frost (April 29) 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 4 – Mar 18 Transplant outdoors: May 6 – May 13 |
| Peppers | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: May 13 – May 20 |
| Eggplant | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: May 13 – May 20 |
| Broccoli | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: Apr 1 – Apr 15 |
| Cabbage | Start seeds indoors: Feb 18 – Mar 4 Transplant outdoors: Apr 1 – Apr 15 |
| Onions (sets) | Plant outdoors: Apr 1 – Apr 15 |
| Peas | Sow outdoors: Mar 18 – Apr 1 |
| Spinach | Sow outdoors: Mar 18 – Apr 1 |
| Lettuce | Sow outdoors: Apr 1 – Apr 15 |
| Carrots | Sow outdoors: Apr 1 – Apr 15 |
| Potatoes | Plant outdoors: Apr 1 – Apr 15 |
| Beans | Sow outdoors: May 6 – May 13 |
| Sweet corn | Sow outdoors: May 6 – May 13 |
| Cucumbers | Sow outdoors: May 6 – May 13 |
| Squash & zucchini | Sow outdoors: May 6 – May 13 |
| Basil | Start seeds indoors: Mar 18 – Apr 1 Transplant outdoors: May 6 – May 13 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 12 (8 weeks before the average first fall frost on Oct 7).
Useful for zone 5a 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
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 15 | Apr 29 | May 12 |
| First 32°F frost in fall is before | Oct 23 | Oct 7 | Sep 22 |
How to read it: in spring there is a 10% chance of a frost after May 12, so that is a safe date for tender plants. In fall there is a 10% chance of frost before September 22. A hard freeze (28°F) usually ends around April 18.
Hardiness zone by ZIP code in New Ulm
- 56073 zone 5a
Nearby cities
- North Mankato zone 5a, last frost Apr 30
- Mankato zone 5a, last frost Apr 30
- Saint Peter zone 5a, last frost May 2
- Hutchinson zone 4b, last frost Apr 28
- Fairmont zone 5a, last frost Apr 25
- Waconia zone 4b, last frost May 5
- Chaska zone 4b, last frost May 5
- Willmar zone 4b, last frost Apr 30
Questions
What growing zone is New Ulm, MN?
New Ulm is in USDA Plant Hardiness Zone 5a (average extreme winter low -20°F to -15°F), according to the USDA 2023 map.
When is the last frost in New Ulm?
The average last spring frost (32°F) in New Ulm is April 29. There is still a 10% chance of frost until May 12.
When can I plant tomatoes in New Ulm?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 6 – May 13. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station New Ulm 2 Se, MN (USC00215887), 2.7 km (1.7 mi) from the city center, elevation 271 m, based on 18 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.