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When to plant Onion in Rowan County, KY

Rowan County's climate puts the Onion spring window between April 2 and April 23. time plantings around the expected last-frost window for best survival. A second sowing from August 15 to August 29 extends the harvest into fall.

When to Plant Onion in Rowan 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.

Rowan County, Kentucky is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 24, giving you a growing season of approximately 191 days.

At an elevation of 2,014 feet, Rowan County receives approximately 49 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Onion during the growing season.

Rowan County, KY (Zone 6b) Moderate season
191 days
Last Spring Frost April 16
191 growing days
First Fall Frost October 24

Rowan County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.7

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 3.8" 0" ❄️ Dormant
Feb 4.2" 0" ❄️ Dormant
Mar 5" 0" ❄️ Dormant
Apr 4.3" 4.1" 0.2" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 5.4" 0" ✅ Rainfall sufficient
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Rowan County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Onion Planting Timeline — Rowan County, KY

Onion Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 – Mar 26
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 2 Apr 2 – Apr 23
Harvest July 16 Jul 16 – Sep 3
Fall Sowing August 15 Aug 15 – Aug 29

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

191 days in Rowan County

Growing Tips for Rowan 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 Rowan County, KY?

Rowan County is in Zone 6b with an average last frost of April 16. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rowan County, KY?

Rowan County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 24.

When should I plant Onion in Rowan County, KY?

In Rowan County, KY, plant Onion after the last frost (around April 16) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Rowan County, KY for Onion?

Rowan 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 Rowan County's climate?

Yes — Onion grows well in Rowan County's temperate climate. Rowan County averages a 191-day frost-free season, with last frost around April 16 and first frost around October 24.

🌱

Your Rowan County Garden Planner — Free

A 22-page printable planner built for Rowan 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 Rowan County, KY. Local conditions may vary. Last updated: July 2026.

Sources & credits

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