Paso Robles, CA planting zone & frost dates
Paso Robles is in USDA hardiness zone 9a. The last spring frost usually comes around March 15 and the first fall frost around November 10, for a growing season of about 238 days.
Planting calendar for Paso Robles
Dates are counted from the average last spring frost (March 15) 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 18 – Feb 1 Transplant outdoors: Mar 22 – Mar 29 |
| Peppers | Start seeds indoors: Jan 4 – Jan 18 Transplant outdoors: Mar 29 – Apr 5 |
| Eggplant | Start seeds indoors: Jan 4 – Jan 18 Transplant outdoors: Mar 29 – Apr 5 |
| Broccoli | Start seeds indoors: Jan 4 – Jan 18 Transplant outdoors: Feb 15 – Mar 1 |
| Cabbage | Start seeds indoors: Jan 4 – Jan 18 Transplant outdoors: Feb 15 – Mar 1 |
| Onions (sets) | Plant outdoors: Feb 15 – Mar 1 |
| Peas | Sow outdoors: Feb 1 – Feb 15 |
| Spinach | Sow outdoors: Feb 1 – Feb 15 |
| Lettuce | Sow outdoors: Feb 15 – Mar 1 |
| Carrots | Sow outdoors: Feb 15 – Mar 1 |
| Potatoes | Plant outdoors: Feb 15 – Mar 1 |
| Beans | Sow outdoors: Mar 22 – Mar 29 |
| Sweet corn | Sow outdoors: Mar 22 – Mar 29 |
| Cucumbers | Sow outdoors: Mar 22 – Mar 29 |
| Squash & zucchini | Sow outdoors: Mar 22 – Mar 29 |
| Basil | Start seeds indoors: Feb 1 – Feb 15 Transplant outdoors: Mar 22 – Mar 29 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 15 (8 weeks before the average first fall frost on Nov 10).
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 | Feb 12 | Mar 15 | Apr 13 |
| First 32°F frost in fall is before | Nov 29 | Nov 10 | Oct 23 |
How to read it: in spring there is a 10% chance of a frost after April 13, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 23. A hard freeze (28°F) usually ends around February 9.
Hardiness zone by ZIP code in Paso Robles
- 93446 zone 9a
- 93447 zone 9a
Nearby cities
- Atascadero zone 9a, last frost Mar 15
- Morro Bay zone 10a
- San Luis Obispo zone 10a, last frost Jan 16
- Los Osos zone 10a
- Grover Beach zone 10a
- Arroyo Grande zone 10a
- Coalinga zone 9b, last frost Feb 14
- Nipomo zone 9b, last frost Feb 4
Questions
What growing zone is Paso Robles, CA?
Paso Robles 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 Paso Robles?
The average last spring frost (32°F) in Paso Robles is March 15. There is still a 10% chance of frost until April 13.
When can I plant tomatoes in Paso Robles?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Mar 22 – Mar 29. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Paso Robles, CA (USC00046730), 0.5 km (0.3 mi) from the city center, elevation 222 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.