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When to Plant Onion in Logan County, OK

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.

Logan County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 3 and the first fall frost is November 3, giving you a growing season of approximately 214 days.

At an elevation of 982 feet, Logan County receives approximately 26.8 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Onion during the growing season.

Logan County, OK (Zone 7a) Long season
214 days
Last Spring Frost April 3
214 growing days
First Fall Frost November 3

Logan County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.3

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 0.7" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 4.3" 3.3" 1" 💧 Light watering
May 4.3" 3.4" 0.9" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 3.5" 0.8" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2.2" 2.1" 💧 Light watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 4.3" 1" 3.3" 🚿 Regular watering
Dec 0.8" 0" ❄️ Dormant

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

Onion Planting Timeline — Logan County, OK

Onion Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 20 Mar 20 – Apr 10
Harvest July 3 Jul 3 – Aug 21
Fall Sowing August 25 Aug 25 – Sep 8

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

214 days in Logan County

Growing Tips for Logan 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 Logan County, OK?

Logan County is in Zone 7a with an average last frost of April 3. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is Logan County, OK?

Logan County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 3 and first fall frost is November 3.

🌱

Your Logan County Garden Planner — Free

A 22-page printable planner built for Logan 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.

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 Logan County, OK. Local conditions may vary. Last updated: July 2026.

Sources & credits

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