Plant Basil in Zone 10b
Seed-starting, transplant & harvest dates for USDA Zone 10b
Zone 10b averages 350 frost-free days, running from a last spring frost around January 15 to a first fall frost around December 31. Basil needs roughly 60 days from planting out to first harvest, so it uses about 17 percent of that window. Basil is a tender crop, which is what decides where in the window it belongs.
Because basil needs a head start, sow seed indoors around Dec 4, about 6 weeks ahead of the Zone 10b last frost. Transplants go out around Jan 29. Starting earlier than that in Zone 10b usually backfires: plants outgrow their cells and stall when they finally hit cold soil. At 60 days to harvest, a 350-day Zone 10b season has room for about 4 sowings, so stagger them rather than planting everything at once.
Fall planting: basil in Zone 10b
Basil has no useful fall window in Zone 10b. Basil blackens at the first light frost, so there is no fall window. Move a plant indoors under a light instead.
Basil blackens at the first light frost, so there is no fall window. Move a plant indoors under a light instead.
Fall dates are counted backward from the Zone 10b average first frost, not forward from a sowing date. See the fall planting calendar by zone for the full method.
Spring vs fall basil in Zone 10b
| Planting | Sow or start | In the ground | Harvest |
|---|---|---|---|
| Spring | Dec 4 | Jan 29 | Mar 30 |
| Fall | — | — | — |
Basil in nearby zones
Further reading on basil
- When to start seeds indoors by zone
Indoor start dates for basil, counted back from your last frost.
- Hardening off seedlings: a schedule
A day by day plan for moving basil seedlings outdoors.
- Best grow lights for seed starting
What light seedlings actually need, and which fixtures deliver it.
Other crops in Zone 10b
Frequently asked questions
When should I start basil in Zone 10b?
Start basil seeds indoors around Dec 4 (Zone 10b).
Can I direct sow basil in Zone 10b?
Yes, direct sow around Jan 29.
Can I plant basil in the fall in Zone 10b?
Basil has no useful fall window in Zone 10b. Basil blackens at the first light frost, so there is no fall window. Move a plant indoors under a light instead.
Will basil survive frost in Zone 10b?
No. Basil is a tender crop and a single light frost ends it, so every Zone 10b planting has to finish before the average first frost.
How many plantings of basil fit in a Zone 10b season?
About 4. Zone 10b averages 350 frost-free days and basil needs roughly 60 days plus a couple of weeks of turnaround, so sowing every 37 days keeps a supply coming.