Lathrop, CA planting zone & frost dates
Lathrop is in USDA hardiness zone 9b. The last spring frost usually comes around February 6 and the first fall frost around December 1, for a growing season of about 304 days.
Planting calendar for Lathrop
Dates are counted from the average last spring frost (February 6) 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: Dec 12 – Dec 26 Transplant outdoors: Feb 13 – Feb 20 |
| Peppers | Start seeds indoors: Nov 28 – Dec 12 Transplant outdoors: Feb 20 – Feb 27 |
| Eggplant | Start seeds indoors: Nov 28 – Dec 12 Transplant outdoors: Feb 20 – Feb 27 |
| Broccoli | Start seeds indoors: Nov 28 – Dec 12 Transplant outdoors: Jan 9 – Jan 23 |
| Cabbage | Start seeds indoors: Nov 28 – Dec 12 Transplant outdoors: Jan 9 – Jan 23 |
| Onions (sets) | Plant outdoors: Jan 9 – Jan 23 |
| Peas | Sow outdoors: Dec 26 – Jan 9 |
| Spinach | Sow outdoors: Dec 26 – Jan 9 |
| Lettuce | Sow outdoors: Jan 9 – Jan 23 |
| Carrots | Sow outdoors: Jan 9 – Jan 23 |
| Potatoes | Plant outdoors: Jan 9 – Jan 23 |
| Beans | Sow outdoors: Feb 13 – Feb 20 |
| Sweet corn | Sow outdoors: Feb 13 – Feb 20 |
| Cucumbers | Sow outdoors: Feb 13 – Feb 20 |
| Squash & zucchini | Sow outdoors: Feb 13 – Feb 20 |
| Basil | Start seeds indoors: Dec 26 – Jan 9 Transplant outdoors: Feb 13 – Feb 20 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Oct 6 (8 weeks before the average first fall frost on Dec 1).
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 31 | Feb 6 | Feb 28 |
| First 32°F frost in fall is before | Dec 26 | Dec 1 | Nov 15 |
How to read it: in spring there is a 10% chance of a frost after February 28, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 15. A hard freeze (28°F) usually ends around January 10.
Hardiness zone by ZIP code in Lathrop
- 95330 zone 9b
Nearby cities
Questions
What growing zone is Lathrop, CA?
Lathrop 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 Lathrop?
The average last spring frost (32°F) in Lathrop is February 6. There is still a 10% chance of frost until February 28.
When can I plant tomatoes in Lathrop?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Feb 13 – Feb 20. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Stockton Metro Ap, CA (USW00023237), 8.6 km (5.3 mi) from the city center, elevation 8 m, based on 29 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.