Blog

When to Plant Potatoes in Washington 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.

Washington County, Ohio is in USDA Zone 6a. The average last spring frost is April 28 and the first fall frost is October 19, giving you a growing season of approximately 174 days.

At an elevation of 803 feet, Washington County receives approximately 30.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Potatoes during the growing season.

Washington County, OH (Zone 6a) Moderate season
174 days
Last Spring Frost April 28
174 growing days
First Fall Frost October 19

Washington County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (23 days to spare)
Start indoors: Feb 24 Transplant: May 5 🍅 Harvest: Jul 14 – Sep 22
Recommended (50%) ✓ Fits season (20 days to spare)
Start indoors: Mar 3 Transplant: May 12 🍅 Harvest: Jul 21 – Sep 29
Safe Start (90%) ✓ Fits season (14 days to spare)
Start indoors: Mar 23 Transplant: Jun 1 🍅 Harvest: Aug 10 – Oct 19

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 1-2 times/week
Season total 472 gal / 100 sq ft
Drought risk

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

Potatoes needs ~1,591 GDD — county provides 2,914 GDD Excellent fit

Potatoes Planting Timeline โ€” Washington County, OH

Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 โ€“ Mar 17
Transplant Outdoors May 12 May 12 โ€“ May 26
Direct Sow May 5 May 5 โ€“ May 26
Harvest July 21 Jul 21 โ€“ Sep 29

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April โ€”
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 6a

Growing Season

174 days

Growing Tips for Washington 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Potatoes in Washington County, OH?

Washington County is in Zone 6a with an average last frost of April 28. Plan your Potatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Washington County, OH?

Washington County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 28 and first fall frost is October 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Washington County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Washington County, OH. Local conditions may vary. Last updated: April 2026.