GrowZone

Seed-start answer

Start zucchini seeds indoors around Jan 25

In ZIP 95113, start zucchini seeds indoors around Jan 25, about 21 days before the Feb 15 last-frost estimate.

Source: san-jose-mineta frost station, USDA zone 9b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.

This uses ZIP 95113, the San Jose frost station, and the Feb 15 last-frost estimate.

Seed starting schedule

Zucchini dates for San Jose, CA

StepDateHow to use it
Start IndoorsJanuary 25, 2026Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsFebruary 25, 2026Move hardened-off seedlings outside after the frost-risk window.
Direct SowFebruary 25, 2026Sow seed outside when the crop and soil can handle the window.