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When to Plant Sweet Potatoes in Cotton County, OK

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.

Cotton County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 25 and the first fall frost is November 10, giving you a growing season of approximately 230 days.

At an elevation of 1,015 feet, Cotton County receives approximately 20.6 inches of rainfall annually with predominantly loam soil. Summer highs average 92ยฐF, providing good warmth for Sweet Potatoes during the growing season.

Cotton County, OK (Zone 7b) Long season
230 days
Last Spring Frost March 25
230 growing days
First Fall Frost November 10

Cotton County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (77 days to spare)
Start indoors: Jan 24 Transplant: Mar 28 🍅 Harvest: Jun 27 – Aug 15
Recommended (50%) ✓ Fits season (76 days to spare)
Start indoors: Feb 4 Transplant: Apr 8 🍅 Harvest: Jul 8 – Aug 26
Safe Start (90%) ✓ Fits season (69 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
0.4″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,277 gal / 100 sq ft
Sweet Potatoes needs ~1,995 GDD — county provides 4,370 GDD Excellent fit

Sweet Potatoes Planting Timeline โ€” Cotton County, OK

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 โ€“ Feb 18
Transplant Outdoors April 8 Apr 8 โ€“ Apr 22
Direct Sow April 1 Apr 1 โ€“ Apr 22
Harvest July 8 Jul 8 โ€“ Aug 26

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March โ€”
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 7b

Growing Season

230 days

Growing Tips for Cotton 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 Cotton County, OK?

Cotton County is in Zone 7b with an average last frost of March 25. Plan your Sweet Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cotton County, OK?

Cotton County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 25 and first fall frost is November 10.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Cotton County gardeners in Zone 7b 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 Cotton County, OK. Local conditions may vary. Last updated: April 2026.