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When to Plant Onion in Orange County, IN

Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Orange County, Indiana is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 20, giving you a growing season of approximately 189 days.

At an elevation of 1,246 feet, Orange County receives approximately 34.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Onion during the growing season.

Orange County, IN (Zone 6a) Moderate season
189 days
Last Spring Frost April 14
189 growing days
First Fall Frost October 20

Orange County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-7

Drainage

Well Drained

Monthly Watering Guide for Onion

Onion needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Onion Needs Rainfall You Supplement Action
Jan โ€” 1.7" 0" โ„๏ธ Dormant
Feb โ€” 1.7" 0" โ„๏ธ Dormant
Mar โ€” 2.2" 0" โ„๏ธ Dormant
Apr 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
May 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Jun 4.3" 4.6" 0" โœ… Rainfall sufficient
Jul 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Aug 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Sep 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Oct 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Nov โ€” 2.6" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

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

Onion Planting Timeline โ€” Orange County, IN

Onion Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 โ€“ Mar 24
Transplant Outdoors April 14 Apr 14 โ€“ Apr 28
Direct Sow March 31 Mar 31 โ€“ Apr 21
Harvest July 14 Jul 14 โ€“ Sep 1
Fall Sowing August 11 Aug 11 โ€“ Aug 25

Plant 1" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May โ€”
June โ€”
July Harvest
August Fall Sowing Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

189 days in Orange County

Growing Tips for Orange County

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Onion in Orange County, IN?

Orange County is in Zone 6a with an average last frost of April 14. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Orange County, IN?

Orange County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Orange County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Orange County, IN. Local conditions may vary. Last updated: April 2026.