When to Plant Sweet Potatoes in Minnesota
Not related to regular potatoes at all. Sweet potatoes need heat and a long growing season but reward with incredible harvests.
The Short Answer
Minnesota Frost Dates
Your planting dates depend on which part of Minnesota you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern Minnesota | 3a, 3b | May 15 - Jun 1 | Sep 5 - Sep 20 |
| Central Minnesota | 3b, 4a | May 5 - May 20 | Sep 15 - Oct 1 |
| Southern Minnesota | 4a, 4b | Apr 25 - May 10 | Sep 25 - Oct 10 |
Sweet Potatoes Planting Schedule for Minnesota
Northern Minnesota (Zones 3a, 3b)
Average last frost: May 15 - Jun 1 · Average first frost: Sep 5 - Sep 20
Central Minnesota (Zones 3b, 4a)
Average last frost: May 5 - May 20 · Average first frost: Sep 15 - Oct 1
Southern Minnesota (Zones 4a, 4b)
Average last frost: Apr 25 - May 10 · Average first frost: Sep 25 - Oct 10
Growing Sweet Potatoes in Minnesota
Sweet Potatoes in Minnesota's Climate
Sweet potatoes are a stretch in cold climates — the crop needs 90+ days of warm soil and air. Southern zones 5b-5a gardeners can succeed with Beauregard (90 days), black plastic mulch, and raised beds. Northern zone 3-4 gardeners should skip sweet potatoes — the season simply isn't long enough. Container growing on a sun-baked patio sometimes works where in-ground doesn't.
Soil Considerations for Minnesota
Rich prairie soils in south and west. Rocky and thin soils in north. Generally excellent for gardening in southern half. Loose, well-drained soil is especially important for sweet potatoes since the edible portion grows underground. If your soil is heavy clay, consider raised beds.
Minnesota Climate & Growing Season
Long, cold winters. Warm summers. Short but productive growing season with long summer days. Hardy varieties essential. Sweet Potatoes cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
Growing season length varies across Minnesota: Northern Minnesota (3a, 3b) has a last frost around May 15 - Jun 1, while Southern Minnesota (4a, 4b) sees frost end around Apr 25 - May 10. This difference matters for sweet potatoes — transplant timing shifts by several weeks across the state.
Growing Tips
Grow from slips, not seeds. Start slips from a sweet potato in water 8 weeks before transplanting. Cure harvested tubers in warmth for 10 days.
Companion Planting
Plant sweet potatoes alongside these companions for better growth:
Keep sweet potatoes away from:
The Bottom Line
Last reviewed: March 29, 2026