Herb

When to Plant Basil in California

The king of herbs. Basil and tomatoes are best friends in the garden and in the kitchen.

The Short Answer

California's warm climate and diverse culinary traditions make it basil heaven. From the Italian Genovese basil in Bay Area pasta dishes to the Thai basil in San Francisco's Richmond District restaurants to the Holy Basil in Southern California's Indian cuisine, basil is woven into California's food culture. The state's long growing season means basil produces for 6-8 months in most regions — a luxury that northern gardeners can only dream about.

California Frost Dates

Your planting dates depend on which part of California you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Northern California Mountains 5a, 5b, 6a, 6b May 1 - May 25 Sep 20 - Oct 15
Central Valley 9a, 9b Feb 10 - Mar 1 Nov 15 - Dec 5
Southern California Coast 10a, 10b, 11a Jan 1 - Feb 1 Dec 10 - Jan 1
Bay Area 9b, 10a Jan 20 - Feb 15 Nov 25 - Dec 15

Basil Planting Schedule for California

Northern California Mountains (Zones 5a, 5b, 6a, 6b)

Average last frost: May 1 - May 25 · Average first frost: Sep 20 - Oct 15

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Central Valley (Zones 9a, 9b)

Average last frost: Feb 10 - Mar 1 · Average first frost: Nov 15 - Dec 5

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Southern California Coast (Zones 10a, 10b, 11a)

Average last frost: Jan 1 - Feb 1 · Average first frost: Dec 10 - Jan 1

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Bay Area (Zones 9b, 10a)

Average last frost: Jan 20 - Feb 15 · Average first frost: Nov 25 - Dec 15

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Growing Basil in California

State-Specific Growing Tips

Central Valley: transplant from March and produce through October. Bay Area: transplant from May — fog-belt gardens need the warmest microclimate available. Southern California: transplant from March year-round in frost-free areas. Coastal California's cool summers can slow basil production — choose a sheltered, sunny spot and consider black containers that absorb heat. Inland gardeners can grow basil almost effortlessly. California's dry climate dramatically reduces the downy mildew pressure that devastates eastern basil crops.

Recommended Varieties for California

California's multicultural food scene demands variety. Genovese for Italian cooking. Thai for Southeast Asian cuisine. Holy Basil (Tulsi) for Indian dishes. Opal and Dark Opal for visual impact. Mrs. Burns' Lemon for its citrus brightness. African Blue for ornamental and pollinator gardens. UC Master Gardener programs often hold basil variety tastings at summer events.

Common Challenges in California

Fog-belt cool temperatures slow growth in coastal gardens — this is the primary challenge. Aphids colonize basil tips. Whiteflies can build up in warm inland areas. Downy mildew is far less common in California's dry climate but can appear in the Bay Area and coastal gardens where fog creates moisture on leaves. Slugs in coastal gardens.

Growing Tips

Pinch off flower buds to keep leaves producing. Harvest from the top down, cutting just above a leaf pair. Succession plant for season-long supply.

Companion Planting

Plant basil alongside these companions for better growth:

Tomatoes Peppers Oregano

Keep basil away from:

Sage

The Bottom Line

Basil can be grown successfully in California with proper attention to regional frost dates and local growing conditions. Timing varies across the state — Northern California Mountains gardeners work with a last frost around May 1 - May 25, while Bay Area sees frost end around Jan 20 - Feb 15. Choose varieties suited to your region, amend your soil based on its specific needs, and monitor for the pests and diseases most common in your area. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Basil Growing Guide National planting guide with all states California Planting Calendar All plants for California Basil in Alabama Alabama planting dates Basil in Alaska Alaska planting dates Basil in Arizona Arizona planting dates Basil in Arkansas Arkansas planting dates
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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