Red Bluff, CA planting zone & frost dates
Red Bluff is in USDA hardiness zone 9a. The last spring frost usually comes around February 22 and the first fall frost around November 29, for a growing season of about 281 days.
Planting calendar for Red Bluff
Dates are counted from the average last spring frost (February 22) 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 28 – Jan 11 Transplant outdoors: Mar 1 – Mar 8 |
| Peppers | Start seeds indoors: Dec 14 – Dec 28 Transplant outdoors: Mar 8 – Mar 15 |
| Eggplant | Start seeds indoors: Dec 14 – Dec 28 Transplant outdoors: Mar 8 – Mar 15 |
| Broccoli | Start seeds indoors: Dec 14 – Dec 28 Transplant outdoors: Jan 25 – Feb 8 |
| Cabbage | Start seeds indoors: Dec 14 – Dec 28 Transplant outdoors: Jan 25 – Feb 8 |
| Onions (sets) | Plant outdoors: Jan 25 – Feb 8 |
| Peas | Sow outdoors: Jan 11 – Jan 25 |
| Spinach | Sow outdoors: Jan 11 – Jan 25 |
| Lettuce | Sow outdoors: Jan 25 – Feb 8 |
| Carrots | Sow outdoors: Jan 25 – Feb 8 |
| Potatoes | Plant outdoors: Jan 25 – Feb 8 |
| Beans | Sow outdoors: Mar 1 – Mar 8 |
| Sweet corn | Sow outdoors: Mar 1 – Mar 8 |
| Cucumbers | Sow outdoors: Mar 1 – Mar 8 |
| Squash & zucchini | Sow outdoors: Mar 1 – Mar 8 |
| Basil | Start seeds indoors: Jan 11 – Jan 25 Transplant outdoors: Mar 1 – Mar 8 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Oct 4 (8 weeks before the average first fall frost on Nov 29).
Useful for zone 9a 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 | Jan 17 | Feb 22 | Mar 30 |
| First 32°F frost in fall is before | Dec 18 | Nov 29 | Nov 12 |
How to read it: in spring there is a 10% chance of a frost after March 30, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 12. A hard freeze (28°F) usually ends around January 13.
Hardiness zone by ZIP code in Red Bluff
- 96080 zone 9b
Nearby cities
Questions
What growing zone is Red Bluff, CA?
Red Bluff is in USDA Plant Hardiness Zone 9a (average extreme winter low 20°F to 25°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 9b.
When is the last frost in Red Bluff?
The average last spring frost (32°F) in Red Bluff is February 22. There is still a 10% chance of frost until March 30.
When can I plant tomatoes in Red Bluff?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Mar 1 – Mar 8. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Red Bluff Muni Ap, CA (USW00024216), 3.3 km (2.0 mi) from the city center, elevation 108 m, based on 28 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.