Yankton, SD planting zone & frost dates
Yankton is in USDA hardiness zone 5a. The last spring frost usually comes around April 27 and the first fall frost around October 11, for a growing season of about 164 days.
Planting calendar for Yankton
Dates are counted from the average last spring frost (April 27) 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 2 – Mar 16 Transplant outdoors: May 4 – May 11 |
| Peppers | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: May 11 – May 18 |
| Eggplant | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: May 11 – May 18 |
| Broccoli | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: Mar 30 – Apr 13 |
| Cabbage | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: Mar 30 – Apr 13 |
| Onions (sets) | Plant outdoors: Mar 30 – Apr 13 |
| Peas | Sow outdoors: Mar 16 – Mar 30 |
| Spinach | Sow outdoors: Mar 16 – Mar 30 |
| Lettuce | Sow outdoors: Mar 30 – Apr 13 |
| Carrots | Sow outdoors: Mar 30 – Apr 13 |
| Potatoes | Plant outdoors: Mar 30 – Apr 13 |
| Beans | Sow outdoors: May 4 – May 11 |
| Sweet corn | Sow outdoors: May 4 – May 11 |
| Cucumbers | Sow outdoors: May 4 – May 11 |
| Squash & zucchini | Sow outdoors: May 4 – May 11 |
| Basil | Start seeds indoors: Mar 16 – Mar 30 Transplant outdoors: May 4 – May 11 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 16 (8 weeks before the average first fall frost on Oct 11).
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 13 | Apr 27 | May 10 |
| First 32°F frost in fall is before | Oct 23 | Oct 11 | Sep 27 |
How to read it: in spring there is a 10% chance of a frost after May 10, so that is a safe date for tender plants. In fall there is a 10% chance of frost before September 27. A hard freeze (28°F) usually ends around April 18.
Hardiness zone by ZIP code in Yankton
- 57078 zone 5a
Nearby cities
- Vermillion zone 5a, last frost May 3
- Sioux Falls zone 5a, last frost May 1
- Mitchell zone 5a, last frost May 2
- Brookings zone 4b, last frost May 6
- Huron zone 4b, last frost May 6
- Watertown zone 4b, last frost May 7
- Aberdeen zone 4a, last frost May 8
- Rapid City zone 5b, last frost May 3
Questions
What growing zone is Yankton, SD?
Yankton 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 Yankton?
The average last spring frost (32°F) in Yankton is April 27. There is still a 10% chance of frost until May 10.
When can I plant tomatoes in Yankton?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 4 – May 11. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Yankton 2 E, SD (USW00094911), 2.9 km (1.8 mi) from the city center, elevation 360 m, based on 28 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.