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When to Plant Onion in Walsh County, ND

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.

Walsh County, North Dakota is in USDA Zone 3b. The average last spring frost is May 14 and the first fall frost is September 30, giving you a growing season of approximately 139 days.

At an elevation of 553 feet, Walsh County receives approximately 32.7 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, so choose short-season varieties of Onion to ensure they mature before fall.

Walsh County, ND (Zone 3b) Short season
139 days
Last Spring Frost May 14
139 growing days
First Fall Frost September 30

Walsh County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Mar 28 Transplant: May 9 🍅 Harvest: Aug 8 – Sep 12
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Apr 2 Transplant: May 14 🍅 Harvest: Aug 13 – Sep 17
Safe Start (90%) ✓ Fits season (16 days to spare)
Start indoors: Apr 13 Transplant: May 25 🍅 Harvest: Aug 24 – Sep 28

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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 18 gal / 100 sq ft
Drought risk

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

Onion needs ~1,129 GDD — county provides 1,494 GDD Excellent fit

Onion Planting Timeline โ€” Walsh County, ND

Onion Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 โ€“ Apr 16
Transplant Outdoors May 14 May 14 โ€“ May 28
Direct Sow May 7 May 7 โ€“ May 28
Fall Sowing July 8 Jul 8 โ€“ Jul 22
Harvest August 13 Aug 13 โ€“ Sep 17

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors
May Transplant Outdoors Direct Sow
June โ€”
July Fall Sowing
August Harvest
September Harvest
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 3b

Growing Season

139 days

Growing Tips for Walsh 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 Walsh County, ND?

Walsh County is in Zone 3b with an average last frost of May 14. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Walsh County, ND?

Walsh County, North Dakota is in USDA Hardiness Zone 3b. The average last spring frost is May 14 and first fall frost is September 30.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Walsh County gardeners in Zone 3b 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 Walsh County, ND. Local conditions may vary. Last updated: April 2026.