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When to Plant Sweet Potatoes in Cross County, AR

Cross County, Arkansas Zone 8a May

Your May gardening checklist

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 19
Avg. first frost November 7
Soil temp (4") 67°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Time to start sweet potatoes inside

    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.

Cross County, Arkansas is in USDA Zone 8a. The average last spring frost is March 19 and the first fall frost is November 7, giving you a growing season of approximately 233 days.

At an elevation of 531 feet, Cross County receives approximately 53.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°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.

Cross County, AR (Zone 8a) Long season
233 days
Last Spring Frost March 19
233 growing days
First Fall Frost November 7
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Cross County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (80 days to spare)
Start indoors: Jan 22 Transplant: Mar 26 🍅 Harvest: Jun 25 – Aug 13
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Jan 29 Transplant: Apr 2 🍅 Harvest: Jul 2 – Aug 20
Safe Start (90%) ✓ Fits season (78 days to spare)
Start indoors: Feb 18 Transplant: Apr 22 🍅 Harvest: Jul 22 – Sep 9

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 Cross County

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

Soil pH

Your soil pH (5.7–6.7) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Sweet Potatoes.

Organic Matter

Organic matter is moderate (3.1%). 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 Natural rainfall sufficient
Season total 0 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 5" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 4.3" 5.5" 0" ✅ Rainfall sufficient
Apr 4.3" 4.7" 0" ✅ Rainfall sufficient
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 5.3" 0" ✅ Rainfall sufficient
Jul 4.3" 5.5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.5" 0" ✅ Rainfall sufficient
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 4.3" 4.1" 0.2" 💧 Light watering
Dec 4.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Cross 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 ~1,759 GDD — county provides 3,902 GDD Excellent fit

Sweet Potatoes Planting Timeline — Cross County, AR

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors January 29 Jan 29 – Feb 12
Transplant Outdoors April 2 Apr 2 – Apr 16
Direct Sow March 26 Mar 26 – Apr 16
Harvest July 2 Jul 2 – Aug 20

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Direct Sow
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 · Natural rainfall sufficient

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 5.5–6.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

233 days in Cross County

Growing Tips for Sweet Potatoes in Cross County

Direct sow Sweet Potatoes outdoors after March 19 in Cross 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 Cross County, AR?

Cross County is in Zone 8a with an average last frost of March 19. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cross County, AR?

Cross County, Arkansas is in USDA Hardiness Zone 8a. The average last spring frost is March 19 and first fall frost is November 7.

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Your Cross County Garden Planner — Free

A 24-page printable planner built for Cross County (Zone 8a). 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 Cross 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.