Vallejo, CA planting zone & frost dates

Vallejo is in USDA hardiness zone 9b. The last spring frost usually comes around January 17 and the first fall frost around December 27, for a growing season of about 346 days.

USDA hardiness zone9bavg. extreme winter low 25°F to 30°F
Average last spring frostJanuary 1790% chance of no frost after March 4
Average first fall frostDecember 2710% chance of frost by December 4
Growing season346 daysfrost-free days in an average year

Planting calendar for Vallejo

Dates are counted from the average last spring frost (January 17) 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.

CropWhen
TomatoesStart seeds indoors: Nov 22 – Dec 6
Transplant outdoors: Jan 24 – Jan 31
PeppersStart seeds indoors: Nov 8 – Nov 22
Transplant outdoors: Jan 31 – Feb 7
EggplantStart seeds indoors: Nov 8 – Nov 22
Transplant outdoors: Jan 31 – Feb 7
BroccoliStart seeds indoors: Nov 8 – Nov 22
Transplant outdoors: Dec 20 – Jan 3
CabbageStart seeds indoors: Nov 8 – Nov 22
Transplant outdoors: Dec 20 – Jan 3
Onions (sets)Plant outdoors: Dec 20 – Jan 3
PeasSow outdoors: Dec 6 – Dec 20
SpinachSow outdoors: Dec 6 – Dec 20
LettuceSow outdoors: Dec 20 – Jan 3
CarrotsSow outdoors: Dec 20 – Jan 3
PotatoesPlant outdoors: Dec 20 – Jan 3
BeansSow outdoors: Jan 24 – Jan 31
Sweet cornSow outdoors: Jan 24 – Jan 31
CucumbersSow outdoors: Jan 24 – Jan 31
Squash & zucchiniSow outdoors: Jan 24 – Jan 31
BasilStart seeds indoors: Dec 6 – Dec 20
Transplant outdoors: Jan 24 – Jan 31

Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Nov 1 (8 weeks before the average first fall frost on Dec 27).

Frost risk in detail

90% chance50% chance10% chance
Last 32°F frost in spring is afterDec 23Jan 17Mar 4
First 32°F frost in fall is beforeFeb 4Dec 27Dec 4

How to read it: in spring there is a 10% chance of a frost after March 4, so that is a safe date for tender plants. In fall there is a 10% chance of frost before December 4. A hard freeze (28°F) usually ends around January 5.

Hardiness zone by ZIP code in Vallejo

Nearby cities

All cities in California → · Other zone 9b cities →

Questions

What growing zone is Vallejo, CA?

Vallejo 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 Vallejo?

The average last spring frost (32°F) in Vallejo is January 17. There is still a 10% chance of frost until March 4.

When can I plant tomatoes in Vallejo?

Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Jan 24 – Jan 31. Start seeds indoors 6–8 weeks before the last frost.

Frost dates: NOAA U.S. Climate Normals 1991–2020, station Vallejo, CA (USC00049219), 6.1 km (3.8 mi) from the city center, elevation 104 m, based on 7 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.