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When to Plant Marjoram in Warren County, OH

Sweet marjoram is a tender perennial herb with a delicate, sweet oregano-like flavor. It is a cornerstone of Mediterranean cooking and pairs well with meats and vegetables.

Warren County, Ohio is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 22, giving you a growing season of approximately 189 days.

At an elevation of 653 feet, Warren County receives approximately 38.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Marjoram during the growing season.

Warren County, OH (Zone 6b) Moderate season
189 days
Last Spring Frost April 16
189 growing days
First Fall Frost October 22

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Marjoram Planting Timeline — Warren County, OH

Marjoram Planting Calendar

Activity When Date Range
Transplant Outdoors April 23 Apr 23 – May 7
Harvest June 25 Jun 25 – Sep 3

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May Transplant Outdoors
June Harvest
July Harvest
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

189 days in Warren County

Growing Tips for Warren County

Start seeds indoors 6-8 weeks before last frost. Harvest stems just as flower buds appear for peak flavor. In cold climates, grow as an annual or bring containers indoors.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Marjoram in Warren County, OH?

Warren County is in Zone 6b with an average last frost of April 16. Plan your Marjoram planting based on this frost date — see the calendar above for exact timing.

What planting zone is Warren County, OH?

Warren County, Ohio is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 22.

🌱

Your Warren County Garden Planner — Free

A 22-page printable planner built for Warren County (Zone 6b). 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 Warren County, OH. Local conditions may vary. Last updated: July 2026.

Sources & credits

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