Twentynine Palms, CA planting zone & frost dates
Twentynine Palms is in USDA hardiness zone 9b. The last spring frost usually comes around January 24 and the first fall frost around December 10, for a growing season of about 321 days.
Planting calendar for Twentynine Palms
Dates are counted from the average last spring frost (January 24) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Nov 29 – Dec 13 Transplant outdoors: Jan 31 – Feb 7 |
| Peppers | Start seeds indoors: Nov 15 – Nov 29 Transplant outdoors: Feb 7 – Feb 14 |
| Eggplant | Start seeds indoors: Nov 15 – Nov 29 Transplant outdoors: Feb 7 – Feb 14 |
| Broccoli | Start seeds indoors: Nov 15 – Nov 29 Transplant outdoors: Dec 27 – Jan 10 |
| Cabbage | Start seeds indoors: Nov 15 – Nov 29 Transplant outdoors: Dec 27 – Jan 10 |
| Onions (sets) | Plant outdoors: Dec 27 – Jan 10 |
| Peas | Sow outdoors: Dec 13 – Dec 27 |
| Spinach | Sow outdoors: Dec 13 – Dec 27 |
| Lettuce | Sow outdoors: Dec 27 – Jan 10 |
| Carrots | Sow outdoors: Dec 27 – Jan 10 |
| Potatoes | Plant outdoors: Dec 27 – Jan 10 |
| Beans | Sow outdoors: Jan 31 – Feb 7 |
| Sweet corn | Sow outdoors: Jan 31 – Feb 7 |
| Cucumbers | Sow outdoors: Jan 31 – Feb 7 |
| Squash & zucchini | Sow outdoors: Jan 31 – Feb 7 |
| Basil | Start seeds indoors: Dec 13 – Dec 27 Transplant outdoors: Jan 31 – Feb 7 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Oct 15 (8 weeks before the average first fall frost on Dec 10).
Useful for zone 9b gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Shade cloth — for hot summers
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Dec 22 | Jan 24 | Feb 22 |
| First 32°F frost in fall is before | Jan 1 | Dec 10 | Nov 24 |
How to read it: in spring there is a 10% chance of a frost after February 22, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 24. A hard freeze (28°F) usually ends around January 3.
Hardiness zone by ZIP code in Twentynine Palms
- 92277 zone 9b
- 92278 zone 9b
Nearby cities
- Yucca Valley zone 9a, last frost Mar 14
- Indio zone 10a
- Coachella zone 10a
- Desert Hot Springs zone 10a
- Palm Desert zone 10a
- Rancho Mirage zone 10a
- La Quinta zone 10a
- Cathedral City zone 10a
Questions
What growing zone is Twentynine Palms, CA?
Twentynine Palms is in USDA Plant Hardiness Zone 9b (average extreme winter low 25°F to 30°F), according to the USDA 2023 map.
When is the last frost in Twentynine Palms?
The average last spring frost (32°F) in Twentynine Palms is January 24. There is still a 10% chance of frost until February 22.
When can I plant tomatoes in Twentynine Palms?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Jan 31 – Feb 7. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Twentynine Palms, CA (USC00049099), 1.8 km (1.1 mi) from the city center, elevation 602 m, based on 26 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.