Blog

When to plant Onion in Grant County, KY

Grant County's climate puts the Onion spring window between April 1 and April 22. time plantings around the expected last-frost window for best survival. A second sowing from August 17 to August 31 extends the harvest into fall.

When to Plant Onion in Grant 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.

Grant County, Kentucky is in USDA Zone 6b. The average last spring frost is April 15 and the first fall frost is October 26, giving you a growing season of approximately 194 days.

At an elevation of 2,483 feet, Grant County receives approximately 46.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Onion during the growing season.

Grant County, KY (Zone 6b) Moderate season
194 days
Last Spring Frost April 15
194 growing days
First Fall Frost October 26

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Onion Planting Timeline — Grant County, KY

Onion Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 – Mar 25
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 1 Apr 1 – Apr 22
Harvest July 15 Jul 15 – Sep 2
Fall Sowing August 17 Aug 17 – Aug 31

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

194 days in Grant County

Growing Tips for Grant 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 Grant County, KY?

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

What planting zone is Grant County, KY?

Grant County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 15 and first fall frost is October 26.

When should I plant Onion in Grant County, KY?

In Grant County, KY, plant Onion after the last frost (around April 15) and before the first frost (around October 26). Best results when soil holds above 50°F.

What growing zone is Grant County, KY for Onion?

Grant County sits in USDA Zone 6b. Onion grows reliably in zones 3a through 10b, so it's a good fit here.

Can Onion grow in Grant County's climate?

Yes — Onion grows well in Grant County's temperate climate. Grant County averages a 194-day frost-free season, with last frost around April 15 and first frost around October 26.

🌱

Your Grant County Garden Planner — Free

A 22-page printable planner built for Grant County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.