When to Plant Sweet Potatoes in Darke 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.
Darke County, Ohio is in USDA Zone 5b. The average last spring frost is April 25 and the first fall frost is October 17, giving you a growing season of approximately 175 days.
At an elevation of 921 feet, Darke County receives approximately 38.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Sweet Potatoes to ensure they mature before fall.
Darke County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-7.3
Drainage
Well Drained
Plant Planting Risk Windows
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
Sweet Potatoes Planting Timeline — Darke County, OH
Sweet Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 28 | Feb 28 – Mar 14 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Direct Sow | May 2 | May 2 – May 23 |
| Harvest | August 8 | Aug 8 – Sep 26 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | — |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
90–120 days
Soil pH
5.5 – 6.5
USDA Zone
Zone 5b
Growing Season
175 days
Growing Tips for Darke 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
Level Up Your Garden
Sweet Potatoes in Other Locations
Frequently Asked Questions
When should I plant Sweet Potatoes in Darke County, OH?
Darke County is in Zone 5b with an average last frost of April 25. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Darke County, OH?
Darke County, Ohio is in USDA Hardiness Zone 5b. The average last spring frost is April 25 and first fall frost is October 17.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Darke County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.
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