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When to Plant Black Beans in Mercer County, OH

Black beans are a warm-season legume producing small, dark, protein-rich beans that are a staple in Latin American and Caribbean cuisines.

Mercer County, Ohio is in USDA Zone 6a. 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 874 feet, Mercer County receives approximately 32.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Black Beans to ensure they mature before fall.

Mercer County, OH (Zone 6a) Moderate season
175 days
Last Spring Frost April 25
175 growing days
First Fall Frost October 17

Mercer County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Black Beans Planting Timeline — Mercer County, OH

Black Beans Planting Calendar

Activity When Date Range
Direct Sow May 2 May 2 – May 23
Harvest August 1 Aug 1 – Sep 19

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May 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

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

175 days in Mercer County

Growing Tips for Mercer County

Direct sow after last frost. Provide support for climbing varieties. Allow pods to dry fully on the vine before harvesting. Thresh dried pods by hand or in a pillowcase.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Black Beans in Mercer County, OH?

Mercer County is in Zone 6a with an average last frost of April 25. Plan your Black Beans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mercer County, OH?

Mercer County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 25 and first fall frost is October 17.

🌱

Your Mercer County Garden Planner — Free

A 22-page printable planner built for Mercer County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Mercer County, OH. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.