When to Plant Onions in New Mexico
The backbone of the kitchen garden. Choose short-day, intermediate, or long-day varieties based on your latitude.
The Short Answer
New Mexico Frost Dates
Your planting dates depend on which part of New Mexico you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern New Mexico | 4a, 4b, 5a, 5b | May 5 - May 25 | Sep 15 - Oct 5 |
| Central New Mexico (Albuquerque) | 7a, 7b | Apr 1 - Apr 20 | Oct 15 - Nov 5 |
| Southern New Mexico | 7b, 8a, 8b | Mar 15 - Apr 5 | Oct 25 - Nov 15 |
Onions Planting Schedule for New Mexico
Northern New Mexico (Zones 4a, 4b, 5a, 5b)
Average last frost: May 5 - May 25 · Average first frost: Sep 15 - Oct 5
Central New Mexico (Albuquerque) (Zones 7a, 7b)
Average last frost: Apr 1 - Apr 20 · Average first frost: Oct 15 - Nov 5
Southern New Mexico (Zones 7b, 8a, 8b)
Average last frost: Mar 15 - Apr 5 · Average first frost: Oct 25 - Nov 15
Growing Onions in New Mexico
Onions in New Mexico's Climate
Short-day onions only. Plant transplants from October through December for spring harvest. Short-day varieties like Granex (Vidalia type) and Texas 1015 bulb when days reach just 10-12 hours — perfectly timed for your spring. Do not plant long-day or intermediate varieties — they will never bulb in your day-length pattern.
Soil Considerations for New Mexico
Alkaline desert soils. Low organic matter. Caliche layers common. Heavy amendment with compost essential. Loose, well-drained soil is especially important for onions since the edible portion grows underground. If your soil is heavy clay, consider raised beds.
New Mexico Climate & Growing Season
High desert climate. Intense sun. Low humidity. Wide temperature swings day to night. Irrigation essential. Onions can handle frost well, which is an advantage in New Mexico's climate. You can push planting dates earlier in spring and extend into fall.
Growing season length varies across New Mexico: Northern New Mexico (4a, 4b, 5a, 5b) has a last frost around May 5 - May 25, while Southern New Mexico (7b, 8a, 8b) sees frost end around Mar 15 - Apr 5. This difference matters for onions — but onions handle frost well, so the timing difference is less critical.
Growing Tips
Day length triggers bulbing. Northern gardeners need long-day varieties. Southern gardeners need short-day varieties.
Companion Planting
Plant onions alongside these companions for better growth:
Keep onions away from:
The Bottom Line
Last reviewed: March 29, 2026