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When to Plant Sweet Potatoes in Randolph County, AR

Randolph County, Arkansas Zone 7b May

Top priorities for Randolph County, Arkansas gardeners in May

Welcome to May in Zone 7b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 27
Avg. first frost November 2
Soil temp (4") 67°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Fire up the seed-starting tray: sweet potatoes

    You're about 26 weeks out from your last frost — the perfect window to get these germinating indoors.

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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.

Randolph County, Arkansas is in USDA Zone 7b. The average last spring frost is March 27 and the first fall frost is November 2, giving you a growing season of approximately 220 days.

At an elevation of 308 feet, Randolph County receives approximately 52.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 93°F, providing good warmth for Sweet Potatoes during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Potatoes root diseases.

Randolph County, AR (Zone 7b) Long season
220 days
Last Spring Frost March 27
220 growing days
First Fall Frost November 2
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Randolph County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (69 days to spare)
Start indoors: Jan 29 Transplant: Apr 2 🍅 Harvest: Jul 2 – Aug 20
Recommended (50%) ✓ Fits season (66 days to spare)
Start indoors: Feb 6 Transplant: Apr 10 🍅 Harvest: Jul 10 – Aug 28
Safe Start (90%) ✓ Fits season (66 days to spare)
Start indoors: Feb 26 Transplant: Apr 30 🍅 Harvest: Jul 30 – Sep 17

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 Randolph County

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

Soil pH

Your soil pH (5.5–6.7) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). 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
1.0″/week
Watering frequency Only during dry spells
Season total 7 gal / 100 sq ft

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 4.6" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 4.3" 5.1" 0" ✅ Rainfall sufficient
Apr 4.3" 3.6" 0.7" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 5" 0" ✅ Rainfall sufficient
Aug 4.3" 5.2" 0" ✅ Rainfall sufficient
Sep 4.3" 4.4" 0" ✅ Rainfall sufficient
Oct 4.3" 3.8" 0.5" 💧 Light watering
Nov 4.3" 4.1" 0.2" 💧 Light watering
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Randolph 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 ~2,074 GDD — county provides 4,345 GDD Excellent fit

Sweet Potatoes Planting Timeline — Randolph County, AR

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 6 Feb 6 – Feb 20
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow April 3 Apr 3 – Apr 24
Harvest July 10 Jul 10 – Aug 28

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

220 days in Randolph County

Growing Tips for Sweet Potatoes in Randolph County

Direct sow Sweet Potatoes outdoors after March 27 in Randolph County when soil has warmed and frost danger has passed.

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 Randolph County, AR?

Randolph County is in Zone 7b with an average last frost of March 27. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Randolph County, AR?

Randolph County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is March 27 and first fall frost is November 2.

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Your Randolph County Garden Planner — Free

A 24-page printable planner built for Randolph County (Zone 7b). 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 Randolph County, AR. 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.