Ukiah, CA planting zone & frost dates
Ukiah is in USDA hardiness zone 9a. The last spring frost usually comes around March 19 and the first fall frost around November 20, for a growing season of about 245 days.
Planting calendar for Ukiah
Dates are counted from the average last spring frost (March 19) 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: Jan 22 – Feb 5 Transplant outdoors: Mar 26 – Apr 2 |
| Peppers | Start seeds indoors: Jan 8 – Jan 22 Transplant outdoors: Apr 2 – Apr 9 |
| Eggplant | Start seeds indoors: Jan 8 – Jan 22 Transplant outdoors: Apr 2 – Apr 9 |
| Broccoli | Start seeds indoors: Jan 8 – Jan 22 Transplant outdoors: Feb 19 – Mar 5 |
| Cabbage | Start seeds indoors: Jan 8 – Jan 22 Transplant outdoors: Feb 19 – Mar 5 |
| Onions (sets) | Plant outdoors: Feb 19 – Mar 5 |
| Peas | Sow outdoors: Feb 5 – Feb 19 |
| Spinach | Sow outdoors: Feb 5 – Feb 19 |
| Lettuce | Sow outdoors: Feb 19 – Mar 5 |
| Carrots | Sow outdoors: Feb 19 – Mar 5 |
| Potatoes | Plant outdoors: Feb 19 – Mar 5 |
| Beans | Sow outdoors: Mar 26 – Apr 2 |
| Sweet corn | Sow outdoors: Mar 26 – Apr 2 |
| Cucumbers | Sow outdoors: Mar 26 – Apr 2 |
| Squash & zucchini | Sow outdoors: Mar 26 – Apr 2 |
| Basil | Start seeds indoors: Feb 5 – Feb 19 Transplant outdoors: Mar 26 – Apr 2 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 25 (8 weeks before the average first fall frost on Nov 20).
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Feb 13 | Mar 19 | Apr 15 |
| First 32°F frost in fall is before | Dec 9 | Nov 20 | Nov 2 |
How to read it: in spring there is a 10% chance of a frost after April 15, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 2. A hard freeze (28°F) usually ends around February 6.
Hardiness zone by ZIP code in Ukiah
- 95482 zone 9a
Nearby cities
- Clearlake zone 9a, last frost Apr 10
- Healdsburg zone 9b, last frost Feb 15
- Windsor zone 9a, last frost Mar 2
- Santa Rosa zone 9b, last frost Feb 25
- Rohnert Park zone 9a, last frost Feb 28
- Petaluma zone 9a, last frost Feb 28
- Agua Caliente zone 9b, last frost Mar 2
- Sonoma zone 9b, last frost Mar 2
Questions
What growing zone is Ukiah, CA?
Ukiah is in USDA Plant Hardiness Zone 9a (average extreme winter low 20°F to 25°F), according to the USDA 2023 map.
When is the last frost in Ukiah?
The average last spring frost (32°F) in Ukiah is March 19. There is still a 10% chance of frost until April 15.
When can I plant tomatoes in Ukiah?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Mar 26 – Apr 2. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Ukiah, CA (USC00049122), 0.4 km (0.2 mi) from the city center, elevation 194 m, based on 18 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.