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When to Plant Oregano in Knox County, IN

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

Knox County, Indiana is in USDA Zone 6a. The average last spring frost is April 10 and the first fall frost is October 23, giving you a growing season of approximately 196 days.

At an elevation of 735 feet, Knox County receives approximately 38.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, providing good warmth for Oregano during the growing season.

Knox County, IN (Zone 6a) Moderate season
196 days
Last Spring Frost April 10
196 growing days
First Fall Frost October 23

Knox County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (57 days to spare)
Transplant: Apr 12 🍅 Harvest: Jun 14 – Aug 23
Recommended (50%) ✓ Fits season (56 days to spare)
Transplant: Apr 17 🍅 Harvest: Jun 19 – Aug 28
Safe Start (90%) ✓ Fits season (56 days to spare)
Transplant: May 1 🍅 Harvest: Jul 3 – Sep 11

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.

Soil Compatibility in Knox County

How your county's soil matches Oregano's growing requirements.

Soil pH

Your soil pH (6.0โ€“7.2) is within Oregano's preferred range (6.0โ€“8.0).

Soil Texture

The silt loam soil in Knox County is excellent for Oregano โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Oregano.

How to Plant Oregano

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Oregano

3
successive plantings in your 196-day season

Sow every 6.9 weeks. Last sowing by Jul 25 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Oregano

Oregano needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Oregano Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr 1.3" 3.8" 0" โœ… Rainfall sufficient
May 1.3" 4.4" 0" โœ… Rainfall sufficient
Jun 1.3" 4.8" 0" โœ… Rainfall sufficient
Jul 1.3" 4" 0" โœ… Rainfall sufficient
Aug 1.3" 4.2" 0" โœ… Rainfall sufficient
Sep 1.3" 3.5" 0" โœ… Rainfall sufficient
Oct 1.3" 2.7" 0" โœ… Rainfall sufficient
Nov โ€” 3.1" 0" โ„๏ธ Dormant
Dec โ€” 2.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Knox County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Oregano Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Oregano needs ~1,369 GDD — county provides 3,577 GDD Excellent fit

Oregano Planting Timeline โ€” Knox County, IN

Oregano 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

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.3"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“8 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

196 days in Knox County

Growing Tips for Oregano in Knox County

Direct sow Oregano outdoors after April 10 in Knox County when soil has warmed and frost danger has passed.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Oregano in Knox County, IN?

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

What planting zone is Knox County, IN?

Knox County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 10 and first fall frost is October 23.

๐ŸŒฑ

Plan Your Garden with Confidence

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