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When to Plant Oregano in Hamilton County, OH

Oregano is a robust perennial herb essential to Italian and Greek cuisine. Its pungent, savory leaves intensify in flavor when dried.

Hamilton County, Ohio is in USDA Zone 6a. The average last spring frost is April 16 and the first fall frost is October 21, giving you a growing season of approximately 188 days.

At an elevation of 735 feet, Hamilton County receives approximately 38.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Oregano during the growing season.

Hamilton County, OH (Zone 6a) Moderate season
188 days
Last Spring Frost April 16
188 growing days
First Fall Frost October 21

Hamilton County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (49 days to spare)
Transplant: Apr 17 🍅 Harvest: Jun 19 – Aug 28
Recommended (50%) ✓ Fits season (48 days to spare)
Transplant: Apr 23 🍅 Harvest: Jun 25 – Sep 3
Safe Start (90%) ✓ Fits season (42 days to spare)
Transplant: May 14 🍅 Harvest: Jul 16 – Sep 24

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
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Oregano needs ~1,369 GDD — county provides 3,431 GDD Excellent fit

Oregano Planting Timeline โ€” Hamilton County, OH

Oregano Planting Calendar

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

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 8

USDA Zone

Zone 6a

Growing Season

188 days

Growing Tips for Hamilton County

Start from seed, cuttings, or divisions. Harvest just before flowering for strongest flavor. Cut plants back to a few inches in spring to encourage vigorous new growth.

Companion Planting

Good Companions

Level Up Your Garden

Frequently Asked Questions

When should I plant Oregano in Hamilton County, OH?

Hamilton County is in Zone 6a with an average last frost of April 16. Plan your Oregano planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hamilton County, OH?

Hamilton County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 16 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hamilton County gardeners in Zone 6a 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 Hamilton County, OH. Local conditions may vary. Last updated: April 2026.