Glendora, CA planting zone & frost dates
Glendora 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 Glendora
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).
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 Glendora
- 91740 zone 10a
- 91741 zone 10a
Nearby cities
- Citrus zone 10a, last frost Jan 8
- Azusa zone 10a, last frost Jan 8
- Covina zone 10a, last frost Jan 8
- San Dimas zone 10a, last frost Jan 8
- West Covina zone 10a
- La Verne zone 10a, last frost Jan 8
- Baldwin Park zone 10a
- Duarte zone 10a
Questions
What growing zone is Glendora, CA?
Glendora 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 Glendora?
The average last spring frost (32°F) in Glendora is January 8. There is still a 10% chance of frost until February 18.
When can I plant tomatoes in Glendora?
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), 11.0 km (6.8 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.