Planting Date FinderZone, frost date, planting window

When to plant / California

When to plant onions, green in California

North and North Coast = Monterey County north; South Coast = San Luis Obispo County south; Interior Valleys = Sacramento, San Joaquin, and similar valleys; Desert Valleys = Imperial and Coachella Valleys. Source line on the page: California Master Gardener Handbook, Table 13.2, Adapted from Vegetable Gardening Illustrated 1994.

Source: UC ANR, UC Master Gardener Program, Time of planting, retrieved 2026-10-10.

How this page reads that source: Recommended planting dates: April-July | all year | Aug-Dec | Sept-Jan

North and North Coast

  • April-July (April 1–July 31). The guide gives months, so the dated range uses the first day through the last day of those months.

South Coast

  • all year (January 1–December 31). The guide gives months, so the dated range uses the first day through the last day of those months.

Interior Valleys

  • Aug-Dec (August 1–December 31). The guide gives months, so the dated range uses the first day through the last day of those months.

Desert Valleys

  • Sept-Jan (September 1–January 31). The guide gives months, so the dated range uses the first day through the last day of those months.

City frost pages in California are listed on California.