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When to Plant Marjoram in Jefferson County, IN

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.

Jefferson County, Indiana is in USDA Zone 6a. The average last spring frost is April 10 and the first fall frost is October 21, giving you a growing season of approximately 194 days.

At an elevation of 1,010 feet, Jefferson County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Marjoram during the growing season.

Jefferson County, IN (Zone 6a) Moderate season
194 days
Last Spring Frost April 10
194 growing days
First Fall Frost October 21

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Transplant: Apr 13 🍅 Harvest: Jun 15 – Aug 24
Recommended (50%) ✓ Fits season (54 days to spare)
Transplant: Apr 17 🍅 Harvest: Jun 19 – Aug 28
Safe Start (90%) ✓ Fits season (47 days to spare)
Transplant: May 5 🍅 Harvest: Jul 7 – Sep 15

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
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 493 gal / 100 sq ft
Marjoram needs ~1,312 GDD — county provides 3,395 GDD Excellent fit

Marjoram Planting Timeline โ€” Jefferson County, IN

Marjoram Planting Calendar

Activity When Date Range
Transplant Outdoors April 17 Apr 17 โ€“ May 1
Harvest June 19 Jun 19 โ€“ Aug 28

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 โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

6.5 โ€“ 7.5

USDA Zone

Zone 6a

Growing Season

194 days

Growing Tips for Jefferson 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Marjoram in Jefferson County, IN?

Jefferson County is in Zone 6a with an average last frost of April 10. Plan your Marjoram planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jefferson County, IN?

Jefferson County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 10 and first fall frost is October 21.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jefferson 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 Jefferson County, IN. Local conditions may vary. Last updated: April 2026.