California · zones 7a–10b
When to plant basil in California.
Sow or transplant between Feb 4 to Apr 22 in a typical year, keyed to California's median last frost around Jan 14. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Basil dates for a typical California season.
1 · Start indoors
Dec 24 to Mar 11
About 6 weeks before set-out. Warm spot, real light.
2 · Set out
Feb 4 to Apr 22
Keyed to the ~Jan 14 last frost. Sow 0.25" deep, 8" apart.
Harvest
~40 days later
~0.5 lb per plant over ~12 weeks.
California spans more than one climate: Zone 10 is the most common zone, but the state runs 7a to 10b. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
In California: watch for
The pests that find basil here.
With about 334 frost-free days, basil spends longer in the ground here than in most of the country, which widens the window in which aphids can find it. Scout weekly from midseason and act on the first signs.
Fine webbing and pale stippling in hot, dry spells.
Organic fix: Spray the undersides with water, then insecticidal soap or neem.
Yellowing with gray fuzz underneath, or white powder on top.
Organic fix: Space for airflow, water at the base, spray neem.
Your season math: California gives basil about 334 frost-free days, and it needs roughly 40 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting basil in California: questions
When should I plant basil in California?+
In a typical California year, sow basil or set out transplants between Feb 4 to Apr 22, keyed to the state's median last frost around Jan 14. Your exact dates shift with your ZIP code and microclimate.
When do I start basil seeds indoors in California?+
Start seeds inside about 6 weeks before set-out: roughly Dec 24 to Mar 11 for a typical California season.
What USDA zone is California?+
California spans zones 7a–10b, mostly zone 10. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many basil plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.