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When to Plant Potatoes in Putnam County, OH

Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.

Putnam County, Ohio is in USDA Zone 5b. The average last spring frost is April 23 and the first fall frost is October 22, giving you a growing season of approximately 182 days.

At an elevation of 1,300 feet, Putnam County receives approximately 40.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Potatoes to ensure they mature before fall.

Putnam County, OH (Zone 5b) Moderate season
182 days
Last Spring Frost April 23
182 growing days
First Fall Frost October 22

Putnam County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Feb 18 Transplant: Apr 29 🍅 Harvest: Jul 8 – Sep 16
Recommended (50%) ✓ Fits season (28 days to spare)
Start indoors: Feb 26 Transplant: May 7 🍅 Harvest: Jul 16 – Sep 24
Safe Start (90%) ✓ Fits season (25 days to spare)
Start indoors: Mar 11 Transplant: May 20 🍅 Harvest: Jul 29 – 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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 136 gal / 100 sq ft
Drought risk

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

Potatoes needs ~1,235 GDD — county provides 2,366 GDD Excellent fit

Potatoes Planting Timeline โ€” Putnam County, OH

Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 โ€“ Mar 12
Transplant Outdoors May 7 May 7 โ€“ May 21
Direct Sow April 30 Apr 30 โ€“ May 21
Harvest July 16 Jul 16 โ€“ Sep 24

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 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

70โ€“120 days

Soil pH

5 โ€“ 6.5

USDA Zone

Zone 5b

Growing Season

182 days

Growing Tips for Putnam County

Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Cucumber
  • Squash Summer

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Frequently Asked Questions

When should I plant Potatoes in Putnam County, OH?

Putnam County is in Zone 5b with an average last frost of April 23. Plan your Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Putnam County, OH?

Putnam County, Ohio is in USDA Hardiness Zone 5b. The average last spring frost is April 23 and first fall frost is October 22.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Putnam County gardeners in Zone 5b 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 Putnam County, OH. Local conditions may vary. Last updated: April 2026.