Outdoor transplant window
Early JuneSet slips after frost danger has passed and the soil has warmed. Starting roots in mid-April creates the planting stock for this short season.
Regional growing guide · Minnesota
Growing sweet potatoes in Minnesota
Sweet potatoes can be grown in Minnesota by starting slips early and transplanting outdoors once the season is warm. UMN Extension places outdoor planting in early June.
Minnesota short-season timing
Growing for a home garden? See the general sweet potato guide.
Regional crop context
Sweet potatoes in Minnesota
UMN Extension’s calendar reflects the short frost-free season: start roots indoors in mid-April, then plant slips outdoors in early June.
UMN’s calendar is home-garden guidance. The regional climate panel and crop-level field references provide additional context for larger-scale planning.
Step 1 of 7 · Assess
Check the field and production system before ordering slips
Coordinate clean slip supply, field preparation, planting water, setter capacity, weed control and digging space before committing acreage.
6 topics still to verify· planning aid only, not a suitability score
Selections stay in this browser tab and are not saved or sent anywhere.
Need a field-specific review? Run a coordinate-level farm audit for localized conditions.
Read the field history before selecting slips
Root-knot nematodes, wireworms and other soilborne pests affect marketable roots. Soil sampling, clean planting material, crop rotation and equipment sanitation are the first decisions; chemical treatment depends on current field results and product labels.
Step 2 of 7 · Plan
Choose a transplant window in Minnesota
UMN Extension gives early June as the outdoor planting period. The field date still depends on soil warmth, frost risk and the maturity period of the selected variety.
Historical regional climate
Monthly soil and air temperature context
Green tiles are months whose mean soil temperature is in the 77–86°F root-development range; all other tiles are neutral and show the value. Early, main and late badges mark the 10th, median and 90th-percentile dates for reaching 18.3°C for 4 consecutive days. Bar height shows the mean.
Early soil-warming date
May 26
10th percentile
Median soil-warming date
June 08
median year
Late soil-warming date
June 21
90th percentile
- Early · 10th percentile
- Main · median
- Late · 90th percentile
- 77–86°F root range
- Cooler or warmer than the root range
June: regional monthly means
- Modeled soil temperature
- 18.8°C · 0–7 cm model layer
- Mean air temperature
- 19.5°C
Months whose historical mean soil temperature reaches the 65°F reference: June, July, August. Months in the 77–86°F root-development range: none in the available record. These are monthly regional averages, not planting dates or a frost check.
Open-Meteo · era5_land · 1996-01-01 to 2025-12-31 · Reference point 46.00°N, 94.50°W. Soil-temperature values are modeled at 0–7 cm model layer; the 65°F (18.3°C) transplant reference comes from a 4-inch field measurement. Use the regional calendar above with a current field reading.
Set the field date from a real soil reading
Sweet potato slips establish best after frost risk has passed and the soil is at least 65°F (18.3°C) at 4 inches. That is a field measurement; the climate strip above shows regional history.
Match the date to variety maturity
Use the regional crop duration and expected fall cutoff to choose a variety and harvest date. Confirm market grade, digging capacity and curing space before planting.
Step 3 of 7 · Prepare
Build an aerated bed and keep the crop sequence clean
Sweet potatoes develop best in a loose, well-drained root zone. Shape beds to the field soil and drainage pattern, and keep saturated ground out of the planting plan.
The bed does several jobs
- Improves aeration and drainage around developing roots.
- Warms the crop zone for a warm-season transplant.
- Gives the setter and digger a consistent row to follow.
Keep bed height and shape consistent with soil texture, water movement and the equipment used on the farm.
Set fertility from the field test
Base pH and fertilizer rates on representative soil tests. Avoid excess nitrogen, which can favor vine growth over marketable storage-root sizing.
Step 4 of 7 · Establish
Plant slips, not seed, and calculate the stand
Sweet potatoes are established from vegetative vine cuttings called slips. Buy clean, healthy slips in the target variety and quantity, and keep them shaded and moist until planting.
Regional starting pattern
- Between rows
- 36–48 in (91–122 cm)
- Within row
- 8–14 in (20–36 cm)
- Transplant depth
- 3–4 in (7.6–10.2 cm), with at least three nodes covered
The UMN calendar does not specify commercial field spacing. The bounded calculator uses a published U.S. field pattern as a starting point; adapt the row setting to equipment.
Planting calculator
Estimate slips for your field
Estimated slips
12,446
at 42 × 12 in
Estimate = field area ÷ row-by-slip spacing. Keep values within the published bounds, then match the starting pattern to equipment and target root grade. Headlands and replant allowance are not included.
Step 5 of 7 · Manage
Protect the establishment period and the root grade
The first weeks determine how evenly slips establish and how the crop competes. Protect the crop from early weed competition and scout for wireworms, flea beetles and root-knot nematodes. Use field history, clean planting material and equipment sanitation to reduce avoidable risk.
Get water onto the slip at planting
Water immediately after setting and maintain enough moisture for root establishment. Track rainfall and soil moisture; avoid keeping beds saturated.
Keep the field clean while the crop closes rows
Scout early and maintain a weed-free start through canopy closure. Choose current control methods for the farm’s production system.
Scout below the canopy as well
Wireworms, flea beetles and root-knot nematodes can downgrade roots. Keep field history and scouting records tied to each harvest lot.
Keep tools and planting stock clean
Use certified or otherwise clean slips, avoid carrying soil on slips, and clean equipment after infested fields to limit movement of nematodes and soilborne disease.
Step 6 of 7 · Harvest
Dig at the planned size, cure quickly and protect the skin
Use an early-maturing variety and harvest before frost. The limited Minnesota season makes slip date and crop duration especially important.
Harvest period
Choose a short-season variety; harvest before frost.
Plan by variety, market size, planting date, field condition and frost risk.
Cure
80–85°F · 85–90% RH
A crop-level curing reference is 7–10 days with airflow; use the facility and buyer protocol for the harvested lot.
Store
55–60°F · about 85% RH
Maintain stable temperature, humidity and ventilation after curing.
Step 7 of 7 · Reference
Evidence behind the Minnesota guide
View references (4)
Minnesota sweet potato start and outdoor planting timing; garden calendar.
- 2. Washington State University Extension — Sweetpotato Production PracticesPublished January 2026
Crop-level soil-temperature context, bed preparation, equipment-led row spacing and the relationship between plant density and root size.
- 3. University of Missouri Extension — Growing Sweet PotatoesReviewed March 2026; originally published September 2017
Crop-level transplant establishment, slips, frost sensitivity and raised-bed practice. Missouri calendar dates are not applied to other regions.
- 4. Texas A&M AgriLife — Sweet Potato commercial crop profileOlder technical profile; undated PDF
Shared crop-level reference for curing and storage conditions. Its Texas planting calendar is used only on the Texas page.
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