When to plant summer squash & zucchini in Sacramento, California

January 26 – February 9

Transplant outdoors · typical Sacramento year

Climate basis: NOAA station Sacramento 5 Ese, CA (USW00023271), 5 mi (7 km) from downtown Sacramento (ZCTA 95814 centroid), elevation 38 ft, on the 1991–2020 climate normals. Transplant summer squash & zucchini outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (January 12). One year in ten still freezes after February 8.

Last spring freezeJanuary 121-in-10 after Feb 8
First fall freezeDecember 161-in-10 before Nov 28
Frost-free season341 daysmedian at 32°F
USDA zone9b25 to 30°F winter low not frost timing

The Sacramento year

Start seeds indoorsDec 29 – Jan 5
Transplant outdoorsJan 26 – Feb 9
Direct-sow outdoorsJan 26 – Feb 9
  • indoors under lights
  • in the garden
  • frost-free season
  • 1-in-10 years still freeze to Feb 8
Summer squash & zucchini in Sacramento · freeze context from Sacramento 5 Ese, CA, 1991–2020 normals.

Every method, with its sources

Start seeds indoors

Dec 29 – Jan 5

Sow in pots 3–4 weeks before the outdoor window opens (UNH 3–4 weeks; Missouri G6570 3–5 weeks). Anchored to the median last spring freeze (Jan 12). University of New Hampshire Extension · University of Missouri Extension

Transplant outdoors

Jan 26 – Feb 9

UNH: set out 2 weeks after last frost; Purdue very-tender class agrees. Anchored to the median last spring freeze (Jan 12). University of New Hampshire Extension · Purdue University Extension

Direct-sow outdoors

Jan 26 – Feb 9

Purdue: very tender — at least two weeks after the average last frost. Penn State earliest sowing May 15 (+14 days) agrees. Anchored to the median last spring freeze (Jan 12). Purdue University Extension · Penn State Extension (York County Master Gardeners)

Variety assumption: Assumes an average zucchini-type variety (about 50–60 days from seed; Penn State lists 60).

These windows describe typical years (1991–2020 climate normals), not this year's forecast. Freezes happen outside them — especially in frost pockets, valleys, and urban edges. Watch the forecast before committing tender plants.

This week, not a typical year:
Crop rule sources (4)

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