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Seed Starting Calendar for California

Median last frost from Jan 3 to May 28 across California

NOAA stations
344
Median last frost, Fresno
Jan 14
Passed in 9 of 10 years
Feb 11
Planting months

University of California Agriculture and Natural Resources (UC ANR) Cooperative Extension planting months for California

In California the planting calendar runs by the month more than by a frost date, and the extension publishes those months region by region. Each filled cell is a month the guide gives for planting that crop.

Interior Contra Costa County (Sunset Zones 14, 15, 16; inland Bay Area)

CropJanFebMarAprMayJunJulAugSepOctNovDec
tomatoMay
pepperFebMay
eggplantFebApr
broccoliFebMarOctNov
cabbageFebMarSepOctNov
cauliflowerFebMarSepOct
celeryFebMarMayJun
lettuce (leaf)FebMarAprMayAugSepOctNov
onionJanFebMarAprMayJunJulAugSepOctNovDec
peasFebMarAugSep
spinachMarAprSepOct
carrotFebMarAprMayAugSepOct
beetsMarAprMayJunJulAugSep
beans (snap)MayJunJul
sweet cornMayJunJul
cucumberMarAprMayJun
summer squashAprMay
winter squashAprMay
pumpkinMay
cantaloupeAprMayJun
watermelonAprMay

Planting months from University of California Agriculture and Natural Resources (UC ANR) Cooperative Extension, Contra Costa County Vegetable Planting Guide for Interior Regions, read 2026-09-21. Tomatoes in Interior Contra Costa County: May.

Last frost

Last spring frost dates in California

Sacramento and Fresno pass their median last frost in mid January, Crescent City on the north coast around Jan 30, and Tahoe City in the Sierra not until about Jun 9, a spread of nearly five months in one state.

Three dates per station from the NOAA 1991 to 2020 normals. The median is the date half of springs run past. The last column is the date the last 32°F night has passed by in 9 years out of 10, the one to hold tender transplants for.

StationElevationEarly (1 in 10 years later than this)Median last frostPassed in 9 of 10 yearsMedian first fall frost
SacramentoSacramento 5 ESE, USW0002327138 ftDec 18Jan 12Feb 8Dec 16
FresnoFresno Yosemite Intl Airport, USW00093193333 ftDec 22Jan 14Feb 11Dec 14
Imperial County AirportImperial County Airport, USW00003144-58 ftDec 18Jan 14Feb 15Dec 24
Crescent City McNamara AirportCrescent City McNamara Airport, USW0002428656 ftDec 18Jan 30Mar 13Dec 25
Tahoe CityTahoe City, USC000487586,230 ftMay 26Jun 9Jun 25Sep 25
Crop chart

When to start seeds in California, spring 2027

Counted back from the median last frost at Fresno, January 14. Pick another station to redraw the chart for it.

Seed starting calendar for Fresno, California, spring 2027OctNovDecJanFebOnion (from seed)Onion (from seed): start indoors Oct 8 to Oct 22Onion (from seed): harden off Dec 3 to Dec 17Onion (from seed): set out Dec 17 to Dec 24PepperPepper: start indoors Nov 19 to Dec 3Pepper: harden off Jan 14 to Jan 28Pepper: set out Jan 28 to Feb 4EggplantEggplant: start indoors Nov 19 to Dec 3Eggplant: harden off Jan 14 to Jan 28Eggplant: set out Jan 28 to Feb 4TomatoTomato: start indoors Nov 26 to Dec 10Tomato: harden off Jan 7 to Jan 21Tomato: set out Jan 21 to Jan 28BroccoliBroccoli: start indoors Nov 5 to Nov 19Broccoli: harden off Dec 3 to Dec 17Broccoli: set out Dec 17 to Dec 31CabbageCabbage: start indoors Nov 5 to Nov 19Cabbage: harden off Dec 3 to Dec 17Cabbage: set out Dec 17 to Dec 24LettuceLettuce: start indoors Nov 12 to Nov 19Lettuce: harden off Dec 3 to Dec 17Lettuce: set out Dec 17 to Dec 24BasilBasil: start indoors Dec 3 to Dec 17Basil: harden off Jan 14 to Jan 28Basil: set out Jan 28 to Feb 4CucumberCucumber: start indoors Dec 24 to Dec 31Cucumber: harden off Jan 7 to Jan 21Cucumber: set out Jan 21 to Jan 28Cucumber: sow outdoors Jan 14 to Jan 21Summer squashSummer squash: start indoors Dec 31 to Jan 7Summer squash: harden off Jan 14 to Jan 28Summer squash: set out Jan 28 to Feb 4Summer squash: sow outdoors Jan 14 to Jan 21PeasPeas: sow outdoors Dec 17 to Dec 31CarrotCarrot: sow outdoors Dec 31 to Jan 14BeansBeans: sow outdoors Jan 14 to Jan 21Sweet cornSweet corn: sow outdoors Jan 14 to Jan 21Median last frost Jan 149 in 10 years Feb 11
Start indoorsHarden offSet outSow outdoorsMedian last frostLast freeze passed in 9 of 10 years
Every crop, counted from a median last frost of January 14
CropStart indoorsSet outSow outdoorsFrost class
TomatoNov 26 to Dec 10Jan 21 to Jan 28Tender, very tender
PepperNov 19 to Dec 3Jan 28 to Feb 4Tender, very tender
EggplantNov 19 to Dec 3Jan 28 to Feb 4Tender, very tender
BasilDec 3 to Dec 17Jan 28 to Feb 4Tender
CeleryOct 22 to Nov 5Jan 14 to Jan 21Tender
CucumberDec 24 to Dec 31Jan 21 to Jan 28Jan 14 to Jan 21Tender
Summer squashDec 31 to Jan 7Jan 28 to Feb 4Jan 14 to Jan 21Tender
Winter squashDec 31 to Jan 7Jan 28 to Feb 4Jan 28 to Feb 4Tender, very tender
PumpkinDec 31 to Jan 7Jan 28 to Feb 4Jan 28 to Feb 4Tender, very tender
Melon (cantaloupe)Dec 31 to Jan 7Jan 28 to Feb 4Tender, very tender
WatermelonDec 24 to Jan 7Jan 28 to Feb 4Tender, very tender
Onion (from seed)Oct 8 to Oct 22Dec 17 to Dec 24Hardy
LeekOct 8 to Oct 22Dec 17 to Dec 24Hardy
ParsleyOct 15 to Oct 22Dec 24 to Dec 31Half-hardy
BroccoliNov 5 to Nov 19Dec 17 to Dec 31Hardy
Brussels sproutsNov 5 to Nov 19Dec 17 to Dec 31Hardy
CabbageNov 5 to Nov 19Dec 17 to Dec 24Hardy
CauliflowerNov 19 to Dec 3Dec 31 to Jan 7Half-hardy
KaleNov 5 to Nov 19Dec 17 to Dec 24Hardy
LettuceNov 12 to Nov 19Dec 17 to Dec 24Hardy
Swiss chardNov 19 to Dec 3Dec 31 to Jan 7Dec 17 to Dec 24Half-hardy
SpinachOct 22 to Nov 5Dec 3 to Dec 24Dec 17 to Dec 31Hardy
PeasDec 17 to Dec 31Hardy
RadishDec 17 to Dec 31Hardy
CarrotDec 31 to Jan 14Half-hardy
BeetDec 31 to Jan 14Half-hardy
BeansJan 14 to Jan 21Tender
Sweet cornJan 14 to Jan 21Tender
Six square pots of dark compost seen from above, each holding a single seedling with two narrow seed leaves
Tomato seedlings at the seed leaf stage, one to a pot. The University of Minnesota Extension holds off on fertilizer until a seedling has several sets of true leaves, then feeds at quarter strength once a week. “Tomato Seedlings (49768696597)” by Amanda Slater from Coventry, West Midlands, UK, CC BY-SA 2.0
Extension guide

What UC ANR advises

University of California Agriculture and Natural Resources (UC ANR) Cooperative Extension publishes the planting guide California gardeners work from, Contra Costa County Vegetable Planting Guide for Interior Regions.

“MAY 1: Plant seedlings after May 1. Start seeds indoors 6-8 weeks before transplant.”
University of California Agriculture and Natural Resources (UC ANR) Cooperative Extension, Contra Costa County Vegetable Planting Guide for Interior Regions, quoted exactly.
“Be aware of both the approximate first and last frost dates in your area and protect plants if frost is expected.”
University of California Agriculture and Natural Resources (UC ANR) Cooperative Extension, Time of planting, UC Master Gardener Program, quoted exactly.
“MAY 1: Plant seedlings after May 1. Start seeds indoors 6-8 weeks before transplant.”
University of California Agriculture and Natural Resources (UC ANR) Cooperative Extension, on tomato, quoted exactly.
“BY MARCH 1ST: Start seeds indoors. Set out seedlings when night temperatures are above 45° F (about May in interior locations).”
University of California Agriculture and Natural Resources (UC ANR) Cooperative Extension, on pepper, quoted exactly.
“BY MARCH 1ST: Start seeds indoors by March 1. Set out after all danger of frost or after April 15th.”
University of California Agriculture and Natural Resources (UC ANR) Cooperative Extension, on eggplant, quoted exactly.
“FEBRUARY-MARCH OR OCT-NOV: Plant seedlings. Start seeds 6 weeks before transplant.”
University of California Agriculture and Natural Resources (UC ANR) Cooperative Extension, on broccoli, quoted exactly.
A gardener kneeling beside a raised bed setting a young tomato plant into dark soil, an empty nursery pot beside her
Setting out a tomato in June at a community garden. Tender crops go out after the last frost, and after a week or two of hardening off outdoors. “Volunteer planting heirloom tomato (4704185147)”, Pacific Southwest Region 5, Public domain

Seed starting questions for California

Frost dates from NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal, by station (v1.0.1). Planting guidance from University of California Agriculture and Natural Resources (UC ANR) Cooperative Extension, quoted exactly. Seed starting weeks from UNH Cooperative Extension. Compiled 2026-09-21.

First frost in CaliforniaThe other end of the season: when fall frost ends the tender crops.Soil temperatureBeans, corn and squash sown direct wait on warm soil as well as the last frost.California lawn care calendarSpring seeding, feeding and mowing dates on the same climate.Fall planting calendarGarlic, cool season crops and a second sowing window in the fall.Frost dates by ZIPFirst and last frost odds for any address.

Other states