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When to Plant Sweet Potatoes in Richland County, SC

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.

Richland County, South Carolina is in USDA Zone 8a. The average last spring frost is March 22 and the first fall frost is November 10, giving you a growing season of approximately 233 days.

At an elevation of 88 feet, Richland County receives approximately 57.8 inches of rainfall annually with predominantly clay loam soil. Summer highs average 97ยฐF, so Sweet Potatoes may need afternoon shade and extra watering during peak heat. Clay soil retains moisture well for Sweet Potatoes, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Potatoes root diseases.

Richland County, SC (Zone 8a) Long season
233 days
Last Spring Frost March 22
233 growing days
First Fall Frost November 10

Richland County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (76 days to spare)
Start indoors: Jan 27 Transplant: Mar 31 🍅 Harvest: Jun 30 – Aug 18
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Feb 1 Transplant: Apr 5 🍅 Harvest: Jul 5 – Aug 23
Safe Start (90%) ✓ Fits season (72 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jul 29 – Sep 16

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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Sweet Potatoes needs ~2,389 GDD — county provides 5,300 GDD Excellent fit

Sweet Potatoes Planting Timeline โ€” Richland County, SC

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 1 Feb 1 โ€“ Feb 15
Transplant Outdoors April 5 Apr 5 โ€“ Apr 19
Direct Sow March 29 Mar 29 โ€“ Apr 19
Harvest July 5 Jul 5 โ€“ Aug 23

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Direct Sow
April Transplant Outdoors Direct Sow
May โ€”
June โ€”
July Harvest
August Harvest
September โ€”
October โ€”
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 8a

Growing Season

233 days

Growing Tips for Richland 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 Richland County, SC?

Richland County is in Zone 8a with an average last frost of March 22. Plan your Sweet Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Richland County, SC?

Richland County, South Carolina is in USDA Hardiness Zone 8a. The average last spring frost is March 22 and first fall frost is November 10.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Richland County gardeners in Zone 8a 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 Richland County, SC. Local conditions may vary. Last updated: April 2026.