When to plant sweet potatoes in Sioux Falls, South Dakota

May 15 – May 29

Transplant outdoors · typical Sioux Falls year

Climate basis: NOAA station Sioux Falls, SD (USW00014944), 2 mi (3 km) from downtown Sioux Falls (ZCTA 57104 centroid), elevation 1430 ft, on the 1991–2020 climate normals. Plant sweet potato slips from approximately the dates above, anchored to the median last spring 32°F freeze (May 1). One year in ten still freezes after May 14.

Last spring freezeMay 11-in-10 after May 14
First fall freezeOctober 61-in-10 before Sep 23
Frost-free season157 daysmedian at 32°F
Hard freeze, 28°Apr 22Oct 17kills even hardy greens
USDA zone5a-20 to -15°F winter low not frost timing

The Sioux Falls year

Transplant outdoorsMay 15 – May 29
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to May 14
Sweet potatoes in Sioux Falls · freeze context from Sioux Falls, SD, 1991–2020 normals.

Every method, with its sources

Transplant outdoors

May 15 – May 29

Purdue: very tender (vegetatively propagated) — plant slips at least two weeks after the average last frost. Anchored to the median last spring freeze (May 1). Purdue University Extension

Start seeds indoors

Not calculated

The cited extension guides do not time an indoor seed-starting window for this crop.

Direct-sow outdoors

Not calculated

Sweet potatoes are grown from slips, not seed.

Fall planting

Not calculated

No source-backed fall planting rule exists for this crop in the registry, so no fall window is calculated.

Variety assumption: Assumes an average variety (about 100–120 days of warm weather from slips).

These windows describe typical years (1991–2020 climate normals), not this year's forecast. Freezes happen outside them — especially in frost pockets, valleys, and urban edges. Watch the forecast before committing tender plants.

This week, not a typical year:
Crop rule sources (1)

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