Montclair, CA planting zone & frost dates
Montclair is in USDA hardiness zone 10a. The last spring frost usually comes around January 8 and the first fall frost around December 28, for a growing season of about 354 days.
Planting calendar for Montclair
Dates are counted from the average last spring frost (January 8) 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 13 – Nov 27 Transplant outdoors: Jan 15 – Jan 22 |
| Peppers | Start seeds indoors: Oct 30 – Nov 13 Transplant outdoors: Jan 22 – Jan 29 |
| Eggplant | Start seeds indoors: Oct 30 – Nov 13 Transplant outdoors: Jan 22 – Jan 29 |
| Broccoli | Start seeds indoors: Oct 30 – Nov 13 Transplant outdoors: Dec 11 – Dec 25 |
| Cabbage | Start seeds indoors: Oct 30 – Nov 13 Transplant outdoors: Dec 11 – Dec 25 |
| Onions (sets) | Plant outdoors: Dec 11 – Dec 25 |
| Peas | Sow outdoors: Nov 27 – Dec 11 |
| Spinach | Sow outdoors: Nov 27 – Dec 11 |
| Lettuce | Sow outdoors: Dec 11 – Dec 25 |
| Carrots | Sow outdoors: Dec 11 – Dec 25 |
| Potatoes | Plant outdoors: Dec 11 – Dec 25 |
| Beans | Sow outdoors: Jan 15 – Jan 22 |
| Sweet corn | Sow outdoors: Jan 15 – Jan 22 |
| Cucumbers | Sow outdoors: Jan 15 – Jan 22 |
| Squash & zucchini | Sow outdoors: Jan 15 – Jan 22 |
| Basil | Start seeds indoors: Nov 27 – Dec 11 Transplant outdoors: Jan 15 – Jan 22 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Nov 2 (8 weeks before the average first fall frost on Dec 28).
Useful for zone 10a 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 14 | Jan 8 | Feb 18 |
| First 32°F frost in fall is before | Feb 2 | Dec 28 | Dec 5 |
How to read it: in spring there is a 10% chance of a frost after February 18, so that is a safe date for tender plants. In fall there is a 10% chance of frost before December 5. A hard freeze (28°F) usually ends around an earlier date.
Hardiness zone by ZIP code in Montclair
- 91763 zone 10a
Nearby cities
- Claremont zone 10a, last frost Jan 8
- Ontario zone 10a
- Upland zone 10a
- Chino zone 10a, last frost Jan 17
- Pomona zone 10a, last frost Jan 8
- La Verne zone 10a, last frost Jan 8
- Rancho Cucamonga zone 10a
- Chino Hills zone 10a, last frost Jan 8
Questions
What growing zone is Montclair, CA?
Montclair is in USDA Plant Hardiness Zone 10a (average extreme winter low 30°F to 35°F), according to the USDA 2023 map.
When is the last frost in Montclair?
The average last spring frost (32°F) in Montclair is January 8. There is still a 10% chance of frost until February 18.
When can I plant tomatoes in Montclair?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Jan 15 – Jan 22. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Pomona/Fairplex, CA (USC00047050), 7.0 km (4.3 mi) from the city center, elevation 304 m, based on 16 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.