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When to Plant Sweet Potatoes in Wayne 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.

Wayne County, Utah is in USDA Zone 5b. The average last spring frost is May 14 and the first fall frost is October 2, giving you a growing season of approximately 141 days.

At an elevation of 7,565 feet, Wayne County receives approximately 22.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Sweet Potatoes during the growing season.

Wayne County, UT (Zone 5b) Short season
141 days
Last Spring Frost May 14
141 growing days
First Fall Frost October 2

Wayne County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 6 Transplant: May 15 🍅 Harvest: Aug 14 – Oct 2
Recommended (50%) ✗ May not fit
Start indoors: Mar 19 Transplant: May 28 🍅 Harvest: Aug 27 – Oct 15
Safe Start (90%) ✗ May not fit
Start indoors: Apr 12 Transplant: Jun 21 🍅 Harvest: Sep 20 – Nov 8

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
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 483 gal / 100 sq ft
Drought risk

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

Sweet Potatoes needs ~1,522 GDD — county provides 2,044 GDD Excellent fit

Sweet Potatoes Planting Timeline โ€” Wayne County, UT

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors May 28 May 28 โ€“ Jun 11
Direct Sow May 21 May 21 โ€“ Jun 11
Harvest August 27 Aug 27 โ€“ Oct 15

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Start Indoors
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 5b

Growing Season

141 days

Growing Tips for Wayne 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 Wayne County, UT?

Wayne County is in Zone 5b with an average last frost of May 14. Plan your Sweet Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Wayne County, UT?

Wayne County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is May 14 and first fall frost is October 2.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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