Blog

When to Plant Onion in Morgan 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.

Morgan County, Kentucky is in USDA Zone 6b. The average last spring frost is April 18 and the first fall frost is October 21, giving you a growing season of approximately 186 days.

At an elevation of 3,954 feet, Morgan County receives approximately 52.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Onion during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.

Morgan County, KY (Zone 6b) Moderate season
186 days
Last Spring Frost April 18
186 growing days
First Fall Frost October 21

Morgan 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 (50 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: Jul 10 – Aug 28
Recommended (50%) ✓ Fits season (46 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: Jul 18 – Sep 5
Safe Start (90%) ✓ Fits season (39 days to spare)
Start indoors: Apr 1 Transplant: May 6 🍅 Harvest: Aug 5 – Sep 23

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
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Onion needs ~1,759 GDD — county provides 3,115 GDD Excellent fit

Onion Planting Timeline โ€” Morgan County, KY

Onion Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 โ€“ Mar 28
Transplant Outdoors April 18 Apr 18 โ€“ May 2
Direct Sow April 4 Apr 4 โ€“ Apr 25
Fall Sowing August 12 Aug 12 โ€“ Aug 26
Harvest July 18 Jul 18 โ€“ Sep 5

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 Transplant Outdoors
June โ€”
July Harvest
August Fall Sowing Harvest
September Harvest
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 6b

Growing Season

186 days

Growing Tips for Morgan 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 Morgan County, KY?

Morgan County is in Zone 6b with an average last frost of April 18. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Morgan County, KY?

Morgan County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 18 and first fall frost is October 21.

๐ŸŒฑ

Plan Your Garden with Confidence

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