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When to Plant Onion in Scott 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.

Scott County, Indiana is in USDA Zone 6a. The average last spring frost is April 12 and the first fall frost is October 20, giving you a growing season of approximately 191 days.

At an elevation of 615 feet, Scott County receives approximately 40.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Onion during the growing season.

Scott County, IN (Zone 6a) Moderate season
191 days
Last Spring Frost April 12
191 growing days
First Fall Frost October 20

Scott County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (52 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: Jul 8 – Aug 26
Recommended (50%) ✓ Fits season (51 days to spare)
Start indoors: Mar 8 Transplant: Apr 12 🍅 Harvest: Jul 12 – Aug 30
Safe Start (90%) ✓ Fits season (43 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jul 30 – Sep 17

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
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 692 gal / 100 sq ft
Onion needs ~1,522 GDD — county provides 2,769 GDD Excellent fit

Onion Planting Timeline โ€” Scott County, IN

Onion Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 โ€“ Mar 22
Transplant Outdoors April 12 Apr 12 โ€“ Apr 26
Direct Sow March 29 Mar 29 โ€“ Apr 19
Fall Sowing August 11 Aug 11 โ€“ Aug 25
Harvest July 12 Jul 12 โ€“ Aug 30

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

90โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6a

Growing Season

191 days

Growing Tips for Scott 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Onion in Scott County, IN?

Scott County is in Zone 6a with an average last frost of April 12. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Scott County, IN?

Scott County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 12 and first fall frost is October 20.

๐ŸŒฑ

Plan Your Garden with Confidence

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