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When to Plant Sweet Potatoes in Lafayette County, AR

Lafayette County, Arkansas Zone 8b May

Your May game plan for Lafayette County, Arkansas

Here's what deserves your attention in Lafayette County, Arkansas this month. Everything below is tailored to Zone 8b and timed around your local frost dates.

Avg. last frost March 21
Avg. first frost November 12
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Sow sweet potatoes in trays indoors

    Label every cell. You will absolutely forget which is which otherwise.

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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.

Lafayette County, Arkansas is in USDA Zone 8b. The average last spring frost is March 21 and the first fall frost is November 12, giving you a growing season of approximately 236 days.

At an elevation of 819 feet, Lafayette County receives approximately 54.7 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.

Lafayette County, AR (Zone 8b) Long season
236 days
Last Spring Frost March 21
236 growing days
First Fall Frost November 12

Lafayette County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 days to spare)
Start indoors: Jan 22 Transplant: Mar 26 🍅 Harvest: Jun 25 – Aug 13
Recommended (50%) ✓ Fits season (82 days to spare)
Start indoors: Jan 31 Transplant: Apr 4 🍅 Harvest: Jul 4 – Aug 22
Safe Start (90%) ✓ Fits season (75 days to spare)
Start indoors: Feb 24 Transplant: Apr 28 🍅 Harvest: Jul 28 – Sep 15

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 Lafayette County

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

Soil pH

Your soil pH (5.6–6.7) overlaps with Sweet Potatoes's range (5.5–6.5), though not a perfect match.

Soil Texture

The silt loam soil in Lafayette 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 4.9" 0" ❄️ Dormant
Feb 4.3" 0" ❄️ Dormant
Mar 4.3" 4.6" 0" ✅ Rainfall sufficient
Apr 4.3" 4.8" 0" ✅ Rainfall sufficient
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 6.5" 0" ✅ Rainfall sufficient
Aug 4.3" 5.1" 0" ✅ Rainfall sufficient
Sep 4.3" 4.1" 0.2" 💧 Light watering
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 4.3" 3.9" 0.4" 💧 Light watering
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Lafayette 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 4,661 GDD Excellent fit

Sweet Potatoes Planting Timeline — Lafayette County, AR

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors January 31 Jan 31 – Feb 14
Transplant Outdoors April 4 Apr 4 – Apr 18
Direct Sow March 28 Mar 28 – Apr 18
Harvest July 4 Jul 4 – Aug 22

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

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 8b

📆 Growing Season

236 days in Lafayette County

Growing Tips for Sweet Potatoes in Lafayette County

Direct sow Sweet Potatoes outdoors after March 21 in Lafayette 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 Lafayette County, AR?

Lafayette County is in Zone 8b with an average last frost of March 21. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lafayette County, AR?

Lafayette County, Arkansas is in USDA Hardiness Zone 8b. The average last spring frost is March 21 and first fall frost is November 12.

🌱

Your Lafayette County Garden Planner — Free

A 24-page printable planner built for Lafayette County (Zone 8b). 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 Lafayette 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.