Annual Flower

When to Plant Nasturtiums in California

Edible flowers that double as pest traps. Plant near vegetables to lure aphids away from your food crops.

The Short Answer

Nasturtiums are a California garden staple — they grow almost as weeds in the state's mild climate, self-seeding and spreading along walkways and borders year after year.

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

Nasturtiums 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
2 wks before frost
Transplant Outside
1 wks after frost
Direct Sow
1 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
2 wks before frost
Transplant Outside
1 wks after frost
Direct Sow
1 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
2 wks before frost
Transplant Outside
1 wks after frost
Direct Sow
1 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
2 wks before frost
Transplant Outside
1 wks after frost
Direct Sow
1 wks after frost

Growing Nasturtiums in California

State-Specific Growing Tips

Coastal: sow nearly year-round. Nasturtiums naturalize in California's mild coastal climate. Inland: sow fall through spring. Poor soil preferred. Edible flowers and leaves.

Recommended Varieties for California

All varieties thrive. Alaska, Jewel Mix, Empress of India. California gardeners often let nasturtiums self-seed and naturalize.

Common Challenges in California

Aphids (beneficial as trap crop). Caterpillars. The crop self-seeds so aggressively in California that the main challenge may be controlling its spread.

Growing Tips

Both flowers and young leaves are edible with a peppery taste. Thrives in poor soil — too much nitrogen means all leaves, no flowers.

Companion Planting

Plant nasturtiums alongside these companions for better growth:

Tomatoes Cucumbers Squash Beans

The Bottom Line

Nasturtiums 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

Nasturtiums Growing Guide National planting guide with all states California Planting Calendar All plants for California Nasturtiums in Alabama Alabama planting dates Nasturtiums in Alaska Alaska planting dates Nasturtiums in Arizona Arizona planting dates Nasturtiums 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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