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When to Plant Sweet Potatoes in Piute County, UT

Piute County, Utah Zone 5b May

What to do in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Piute County, Utah.

Avg. last frost May 14
Avg. first frost October 1
Soil temp (4") 36°F
Watering High
Pest pressure Low
Daylight 14.1 hrs
  1. Plant out sweet potatoes

    Frost risk is low now in Piute County, Utah. If you've been covering beds overnight, you can stop.

  2. Plant sweet potatoes from seed, right in the garden

    Your soil is 36°F — warm enough for these to germinate without babying.

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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.

Piute County, Utah is in USDA Zone 5b. The average last spring frost is May 14 and the first fall frost is October 1, giving you a growing season of approximately 140 days.

At an elevation of 7,866 feet, Piute County receives approximately 13.5 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, 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.

Piute County, UT (Zone 5b) Short season
140 days
Last Spring Frost May 14
140 growing days
First Fall Frost October 1

Piute County Soil Profile

Soil Type

Loam

Soil pH

6.3-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 13 Transplant: May 22 🍅 Harvest: Aug 21 – Oct 9
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 16 Transplant: Jun 25 🍅 Harvest: Sep 24 – Nov 12

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.

Soil Compatibility in Piute County

How your county's soil matches Sweet Potatoes's growing requirements.

Soil pH

Your soil pH (6.3–8.0) is more alkaline than Sweet Potatoes prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Piute County is excellent for Sweet Potatoes — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Sweet Potatoes.

How to Plant Sweet Potatoes

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 890 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Sweet Potatoes

Sweet Potatoes needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sweet Potatoes Needs Rainfall You Supplement Action
Jan 0.8" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.3" 0" ❄️ Dormant
May 4.3" 1.6" 2.7" 🚿 Regular watering
Jun 4.3" 0.8" 3.5" 🚿 Regular watering
Jul 4.3" 1.2" 3.1" 🚿 Regular watering
Aug 4.3" 1.4" 2.9" 🚿 Regular watering
Sep 4.3" 1.1" 3.2" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Piute County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Sweet Potatoes Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Sweet Potatoes needs ~1,444 GDD — county provides 1,925 GDD Excellent fit

Sweet Potatoes Planting Timeline — Piute County, UT

Sweet Potatoes Planting Calendar

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

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

140 days in Piute County

Growing Tips for Sweet Potatoes in Piute County

Direct sow Sweet Potatoes outdoors after May 14 in Piute County when soil has warmed and frost danger has passed.

Piute County receives only 14" of rain annually. Sweet Potatoes needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

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

What planting zone is Piute County, UT?

Piute County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is May 14 and first fall frost is October 1.

🌱

Your Piute County Garden Planner — Free

A 24-page printable planner built for Piute County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Piute County, UT. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.