When to Plant Cosmos in New Mexico
Delicate, daisy-like blooms that dance in the breeze. Cosmos thrive in poor soil and practically grow themselves.
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 |
Cosmos 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 Cosmos in New Mexico
Cosmos in New Mexico's Climate
Cosmos grow during the drier months in subtropical zones. Cosmos sulphureus (Bright Lights) handles humidity better than Cosmos bipinnatus (Sensation). Avoid peak summer humidity periods. The flowers are so low-maintenance that they essentially grow as wildflowers in mild climates.
Soil Considerations for New Mexico
Alkaline desert soils. Low organic matter. Caliche layers common. Heavy amendment with compost essential. Make sure soil has warmed to at least 60°F before planting cosmos outside.
New Mexico Climate & Growing Season
High desert climate. Intense sun. Low humidity. Wide temperature swings day to night. Irrigation essential. Cosmos cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
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 cosmos — transplant timing shifts by several weeks across the state.
Growing Tips
Don't over-fertilize — rich soil produces more leaves and fewer flowers. Let some flowers go to seed for next year's crop.
Companion Planting
Plant cosmos alongside these companions for better growth:
The Bottom Line
Last reviewed: March 29, 2026