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When to Plant Sweet Potatoes in Uintah County, UT

Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.

Uintah County, Utah is in USDA Zone 5a. The average last spring frost is May 10 and the first fall frost is October 4, giving you a growing season of approximately 147 days.

At an elevation of 6,372 feet, Uintah County receives approximately 12.7 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Sweet Potatoes during the growing season. With low rainfall, drip irrigation is essential for growing Sweet Potatoes successfully. Mulch heavily to conserve soil moisture.

Uintah County, UT (Zone 5a) Short season
147 days
Last Spring Frost May 10
147 growing days
First Fall Frost October 4

Uintah County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 7 Transplant: May 16 🍅 Harvest: Aug 15 – Oct 3
Recommended (50%) ✗ May not fit
Start indoors: Mar 15 Transplant: May 24 🍅 Harvest: Aug 23 – Oct 11
Safe Start (90%) ✗ May not fit
Start indoors: Apr 7 Transplant: Jun 16 🍅 Harvest: Sep 15 – Nov 3

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,471 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Sweet Potatoes needs ~1,444 GDD — county provides 2,021 GDD Excellent fit

Sweet Potatoes Planting Timeline โ€” Uintah County, UT

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 โ€“ Mar 29
Transplant Outdoors May 24 May 24 โ€“ Jun 7
Direct Sow May 17 May 17 โ€“ Jun 7
Harvest August 23 Aug 23 โ€“ Oct 11

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April โ€”
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July โ€”
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

90โ€“120 days

Soil pH

5.5 โ€“ 6.5

USDA Zone

Zone 5a

Growing Season

147 days

Growing Tips for Uintah County

Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Squash Summer

Level Up Your Garden

Frequently Asked Questions

When should I plant Sweet Potatoes in Uintah County, UT?

Uintah County is in Zone 5a with an average last frost of May 10. Plan your Sweet Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Uintah County, UT?

Uintah County, Utah is in USDA Hardiness Zone 5a. The average last spring frost is May 10 and first fall frost is October 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Uintah County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Uintah County, UT. Local conditions may vary. Last updated: April 2026.