GrowZone

Seed-start answer

Start kale seeds indoors around Dec 21

In ZIP 94102, start kale seeds indoors around Dec 21, about 35 days before the Jan 25 last-frost estimate.

Source: san-francisco-downtown frost station, USDA zone 10a, 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 94102, the San Francisco frost station, and the Jan 25 last-frost estimate.

Seed starting schedule

Kale dates for San Francisco, CA

StepDateHow to use it
Start IndoorsDecember 21, 2025Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsJanuary 11, 2026Move hardened-off seedlings outside after the frost-risk window.
Direct SowJanuary 4, 2026Sow seed outside when the crop and soil can handle the window.