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When to Plant Onion in Carson City, NV

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.

Carson City, Nevada is in USDA Zone 7a. The average last spring frost is May 12 and the first fall frost is October 10, giving you a growing season of approximately 151 days.

At an elevation of 2,716 feet, Carson City receives approximately 8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 98ยฐF, so Onion may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Onion will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Onion successfully. Mulch heavily to conserve soil moisture.

Carson City, NV (Zone 7a) Moderate season
151 days
Last Spring Frost May 12
151 growing days
First Fall Frost October 10

Carson City Soil Profile

Soil Type

Sandy Loam

Soil pH

7.1-8.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jul 31 – Sep 18
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Apr 7 Transplant: May 12 🍅 Harvest: Aug 11 – Sep 29
Safe Start (90%) ✓ Fits season (2 days to spare)
Start indoors: May 2 Transplant: Jun 6 🍅 Harvest: Sep 5 – Oct 24

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
0.2″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,254 gal / 100 sq ft
Drought risk

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

Onion needs ~2,468 GDD — county provides 3,548 GDD Excellent fit

Onion Planting Timeline โ€” Carson City, NV

Onion Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 โ€“ Apr 21
Transplant Outdoors May 12 May 12 โ€“ May 26
Direct Sow April 28 Apr 28 โ€“ May 19
Fall Sowing August 1 Aug 1 โ€“ Aug 15
Harvest August 11 Aug 11 โ€“ Sep 29

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June โ€”
July โ€”
August Fall Sowing 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 7a

Growing Season

151 days

Growing Tips for Carson City

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 Carson City, NV?

Carson City is in Zone 7a with an average last frost of May 12. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Carson City, NV?

Carson City, Nevada is in USDA Hardiness Zone 7a. The average last spring frost is May 12 and first fall frost is October 10.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Carson City 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 Carson City, NV. Local conditions may vary. Last updated: April 2026.