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When to Plant Sweet Potatoes in Highland County, OH

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.

Highland County, Ohio is in USDA Zone 6a. The average last spring frost is April 22 and the first fall frost is October 21, giving you a growing season of approximately 182 days.

At an elevation of 556 feet, Highland County receives approximately 33.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Sweet Potatoes during the growing season.

Highland County, OH (Zone 6a) Moderate season
182 days
Last Spring Frost April 22
182 growing days
First Fall Frost October 21

Highland County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Start indoors: Feb 17 Transplant: Apr 28 🍅 Harvest: Jul 28 – Sep 15
Recommended (50%) ✓ Fits season (28 days to spare)
Start indoors: Feb 25 Transplant: May 6 🍅 Harvest: Aug 5 – Sep 23
Safe Start (90%) ✓ Fits season (26 days to spare)
Start indoors: Mar 11 Transplant: May 20 🍅 Harvest: Aug 19 – Oct 7

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
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 432 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Sweet Potatoes needs ~1,444 GDD — county provides 2,502 GDD Excellent fit

Sweet Potatoes Planting Timeline โ€” Highland County, OH

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 25 Feb 25 โ€“ Mar 11
Transplant Outdoors May 6 May 6 โ€“ May 20
Direct Sow April 29 Apr 29 โ€“ May 20
Harvest August 5 Aug 5 โ€“ Sep 23

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July โ€”
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 6a

Growing Season

182 days

Growing Tips for Highland 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 Highland County, OH?

Highland County is in Zone 6a with an average last frost of April 22. Plan your Sweet Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Highland County, OH?

Highland County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 22 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Highland County gardeners in Zone 6a 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 Highland County, OH. Local conditions may vary. Last updated: April 2026.