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When to Plant Onion in Nowata 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.

Nowata County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 25, giving you a growing season of approximately 201 days.

At an elevation of 839 feet, Nowata County receives approximately 25.2 inches of rainfall annually with predominantly loam soil. Summer highs average 94ยฐF, providing good warmth for Onion during the growing season.

Nowata County, OK (Zone 7a) Long season
201 days
Last Spring Frost April 7
201 growing days
First Fall Frost October 25

Nowata County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (65 days to spare)
Start indoors: Feb 22 Transplant: Mar 29 🍅 Harvest: Jun 28 – Aug 16
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: Jul 7 – Aug 25
Safe Start (90%) ✓ Fits season (65 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jul 21 – Sep 8

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 847 gal / 100 sq ft
Onion needs ~2,152 GDD — county provides 4,120 GDD Excellent fit

Onion Planting Timeline โ€” Nowata County, OK

Onion Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 โ€“ Mar 17
Transplant Outdoors April 7 Apr 7 โ€“ Apr 21
Direct Sow March 24 Mar 24 โ€“ Apr 14
Fall Sowing August 16 Aug 16 โ€“ Aug 30
Harvest July 7 Jul 7 โ€“ Aug 25

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

90โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7a

Growing Season

201 days

Growing Tips for Nowata 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Onion in Nowata County, OK?

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

What planting zone is Nowata County, OK?

Nowata County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Nowata County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

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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 Nowata County, OK. Local conditions may vary. Last updated: April 2026.