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When to Plant Sweet Potatoes in Mayes 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.

Mayes County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 9 and the first fall frost is October 27, giving you a growing season of approximately 201 days.

At an elevation of 777 feet, Mayes County receives approximately 26.4 inches of rainfall annually with predominantly loam soil. Summer highs average 93ยฐF, providing good warmth for Sweet Potatoes during the growing season.

Mayes County, OK (Zone 7a) Long season
201 days
Last Spring Frost April 9
201 growing days
First Fall Frost October 27

Mayes County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jul 16 – Sep 3
Recommended (50%) ✓ Fits season (47 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jul 23 – Sep 10
Safe Start (90%) ✓ Fits season (53 days to spare)
Start indoors: Mar 8 Transplant: May 10 🍅 Harvest: Aug 9 – Sep 27

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
0.6″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,339 gal / 100 sq ft
Sweet Potatoes needs ~2,074 GDD — county provides 3,969 GDD Excellent fit

Sweet Potatoes Planting Timeline โ€” Mayes County, OK

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 โ€“ Mar 5
Transplant Outdoors April 23 Apr 23 โ€“ May 7
Direct Sow April 16 Apr 16 โ€“ May 7
Harvest July 23 Jul 23 โ€“ Sep 10

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July Harvest
August Harvest
September Harvest
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 7a

Growing Season

201 days

Growing Tips for Mayes 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 Mayes County, OK?

Mayes County is in Zone 7a with an average last frost of April 9. Plan your Sweet Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Mayes County, OK?

Mayes County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 9 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

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