GrowZone

Seed-start answer

Start kale seeds indoors around Jan 1

This uses ZIP 85001, the Phoenix frost station, and the Feb 5 last-frost estimate.

Seed starting schedule

Kale dates for Phoenix, AZ

StepDateHow to use it
Start IndoorsJanuary 1, 2026Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsJanuary 22, 2026Move hardened-off seedlings outside after the frost-risk window.
Direct SowJanuary 15, 2026Sow seed outside when the crop and soil can handle the window.