When to Plant Onion in Socorro County, NM
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.
Socorro County, New Mexico is in USDA Zone 6b. The average last spring frost is May 1 and the first fall frost is October 11, giving you a growing season of approximately 163 days.
At an elevation of 5,542 feet, Socorro County receives approximately 14.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 86°F, providing good warmth for Onion during the growing season. Sandy soil warms quickly in spring — great for early planting — 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.
Socorro County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.7-8.5
Drainage
Well Drained
Plant Planting Risk Windows
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
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
Onion Planting Timeline — Socorro County, NM
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 27 | Mar 27 – Apr 10 |
| Transplant Outdoors | May 1 | May 1 – May 15 |
| Direct Sow | April 17 | Apr 17 – May 8 |
| Fall Sowing | August 2 | Aug 2 – Aug 16 |
| Harvest | July 31 | Jul 31 – Sep 18 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
90–120 days
Soil pH
6 – 7
USDA Zone
Zone 6b
Growing Season
163 days
Growing Tips for Socorro 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
Level Up Your Garden
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Socorro County, NM?
Socorro County is in Zone 6b with an average last frost of May 1. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Socorro County, NM?
Socorro County, New Mexico is in USDA Hardiness Zone 6b. The average last spring frost is May 1 and first fall frost is October 11.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Socorro County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.
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