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When to plant Onion in Lyon County, KY

Lyon County gardeners should plant Onion between March 21 and April 11 in spring. With Lyon County's Zone 7a climate (last frost April 4), Onion needs 90–120 days to mature — plant by July 4 for a full harvest. A second sowing from August 23 to September 6 extends the harvest into fall.

When to Plant Onion in Lyon 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.

Lyon County, Kentucky is in USDA Zone 7a. The average last spring frost is April 4 and the first fall frost is November 1, giving you a growing season of approximately 211 days.

At an elevation of 2,809 feet, Lyon County receives approximately 46.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Onion during the growing season.

Lyon County, KY (Zone 7a) Long season
211 days
Last Spring Frost April 4
211 growing days
First Fall Frost November 1

Lyon County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.6

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 4.3" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 4.7" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 5.5" 0" ✅ Rainfall sufficient
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.8" 0.5" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 4.3" 3.4" 0.9" 💧 Light watering
Dec 3.4" 0" ❄️ Dormant

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

Onion Planting Timeline — Lyon County, KY

Onion Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors April 4 Apr 4 – Apr 18
Direct Sow March 21 Mar 21 – Apr 11
Harvest July 4 Jul 4 – Aug 22
Fall Sowing August 23 Aug 23 – Sep 6

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May
June
July Harvest
August Fall Sowing Harvest
September Fall Sowing
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 7a

📆 Growing Season

211 days in Lyon County

Growing Tips for Lyon 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 Lyon County, KY?

Lyon County is in Zone 7a with an average last frost of April 4. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lyon County, KY?

Lyon County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 4 and first fall frost is November 1.

When should I plant Onion in Lyon County, KY?

In Lyon County, KY, plant Onion after the last frost (around April 4) and before the first frost (around November 1). Best results when soil holds above 50°F.

What growing zone is Lyon County, KY for Onion?

Lyon County sits in USDA Zone 7a. Onion grows reliably in zones 3a through 10b, so it's a good fit here.

Can Onion grow in Lyon County's climate?

Yes — Onion grows well in Lyon County's temperate climate. Lyon County averages a 211-day frost-free season, with last frost around April 4 and first frost around November 1.

🌱

Your Lyon County Garden Planner — Free

A 22-page printable planner built for Lyon County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Lyon County, KY. Local conditions may vary. Last updated: June 2026.

Sources & credits

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