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When to Plant Onion in Scott County, KY

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, Kentucky is in USDA Zone 6b. The average last spring frost is April 15 and the first fall frost is October 24, giving you a growing season of approximately 192 days.

At an elevation of 2,255 feet, Scott County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Onion during the growing season.

Scott County, KY (Zone 6b) Moderate season
192 days
Last Spring Frost April 15
192 growing days
First Fall Frost October 24

Scott County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: Jul 8 – Aug 26
Recommended (50%) ✓ Fits season (52 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jul 15 – Sep 2
Safe Start (90%) ✓ Fits season (44 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Aug 1 – Sep 19

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 Scott County

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

Soil pH

Your soil pH (5.3โ€“6.8) overlaps with Onion's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Onion.

How to Plant Onion

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 158 gal / 100 sq ft
Onion needs ~1,444 GDD — county provides 2,640 GDD Excellent fit

Onion Planting Timeline โ€” Scott County, KY

Onion Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 โ€“ Mar 25
Transplant Outdoors April 15 Apr 15 โ€“ Apr 29
Direct Sow April 1 Apr 1 โ€“ Apr 22
Fall Sowing August 15 Aug 15 โ€“ Aug 29
Harvest July 15 Jul 15 โ€“ Sep 2

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
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

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

192 days in Scott County

Growing Tips for Onion in Scott County

Direct sow Onion outdoors after April 15 in Scott County when soil has warmed and frost danger has passed.

Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

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, KY?

Scott County is in Zone 6b with an average last frost of April 15. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Scott County, KY?

Scott County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 15 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

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