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When to Plant Onion in Murray 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.

Murray County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 28 and the first fall frost is November 2, giving you a growing season of approximately 219 days.

At an elevation of 640 feet, Murray County receives approximately 23.2 inches of rainfall annually with predominantly loam soil. Summer highs average 94ยฐF, providing good warmth for Onion during the growing season.

Murray County, OK (Zone 7b) Long season
219 days
Last Spring Frost March 28
219 growing days
First Fall Frost November 2

Murray County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (81 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: Jun 20 – Aug 8
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: Jun 27 – Aug 15
Safe Start (90%) ✓ Fits season (80 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Jul 17 – Sep 4

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.

Soil Compatibility in Murray County

How your county's soil matches Onion's growing requirements.

Soil pH

Your soil pH (6.5โ€“7.7) is more alkaline than Onion prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Murray County is excellent for Onion โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.3%) โ€” Onion will thrive.

How to Plant Onion

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,298 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Apr 4.3" 2.3" 2" ๐Ÿ’ง Light watering
May 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Jun 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Jul 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
Aug 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Sep 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Oct 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Nov 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Murray County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Onion Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Onion needs ~2,152 GDD — county provides 4,489 GDD Excellent fit

Onion Planting Timeline โ€” Murray County, OK

Onion Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 โ€“ Mar 7
Transplant Outdoors March 28 Mar 28 โ€“ Apr 11
Direct Sow March 14 Mar 14 โ€“ Apr 4
Harvest June 27 Jun 27 โ€“ Aug 15
Fall Sowing August 24 Aug 24 โ€“ Sep 7

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

219 days in Murray County

Growing Tips for Onion in Murray County

Direct sow Onion outdoors after March 28 in Murray County when soil has warmed and frost danger has passed.

Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

Murray County receives only 23" of rain annually. Onion needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

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 Murray County, OK?

Murray County is in Zone 7b with an average last frost of March 28. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Murray County, OK?

Murray County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 28 and first fall frost is November 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Murray County gardeners in Zone 7b 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 Murray County, OK. Local conditions may vary. Last updated: April 2026.