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When to Plant Sweet Potatoes in Franklin County, TX

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.

Franklin County, Texas is in USDA Zone 8a. The average last spring frost is March 18 and the first fall frost is November 11, giving you a growing season of approximately 238 days.

At an elevation of 324 feet, Franklin County receives approximately 60 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97ยฐF, so Sweet Potatoes may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Sweet Potatoes will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Potatoes root diseases.

Franklin County, TX (Zone 8a) Long season
238 days
Last Spring Frost March 18
238 growing days
First Fall Frost November 11

Franklin County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.4-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (85 days to spare)
Start indoors: Jan 18 Transplant: Mar 22 🍅 Harvest: Jun 21 – Aug 9
Recommended (50%) ✓ Fits season (84 days to spare)
Start indoors: Jan 28 Transplant: Apr 1 🍅 Harvest: Jul 1 – Aug 19
Safe Start (90%) ✓ Fits season (79 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 511 gal / 100 sq ft
Sweet Potatoes needs ~2,389 GDD — county provides 5,414 GDD Excellent fit

Sweet Potatoes Planting Timeline โ€” Franklin County, TX

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors January 28 Jan 28 โ€“ Feb 11
Transplant Outdoors April 1 Apr 1 โ€“ Apr 15
Direct Sow March 25 Mar 25 โ€“ Apr 15
Harvest July 1 Jul 1 โ€“ Aug 19

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
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

238 days

Growing Tips for Franklin 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 Franklin County, TX?

Franklin County is in Zone 8a with an average last frost of March 18. Plan your Sweet Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Franklin County, TX?

Franklin County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 18 and first fall frost is November 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Franklin 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 Franklin County, TX. Local conditions may vary. Last updated: April 2026.