Plant Spinach 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. Spinach needs roughly 45 days from planting out to first harvest, so it uses about 13 percent of that window. Spinach is a hardy crop, which is what decides where in the window it belongs.
Spinach handles cold soil, so there is no reason to wait for the frost date. Direct sow around Dec 11, roughly 5 weeks before the Zone 10b last frost, as soon as the ground is workable. Sowing at the last frost instead costs you the coolest and best part of the season. At 45 days to harvest, a 350-day Zone 10b season has room for about 5 sowings, so stagger them rather than planting everything at once.
Planting spinach for a fall harvest in Zone 10b
Yes. Plant spinach between November 19 and December 3 in Zone 10b, roughly 6 to 4 weeks before the average first frost, so it roots before the ground freezes.
Spinach sown 4 to 6 weeks before the first frost sizes up, stalls through winter under a row cover, and restarts weeks before anything can be sown in spring.
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 spinach in Zone 10b
| Planting | Sow or start | In the ground | Harvest |
|---|---|---|---|
| Spring | Dec 11 | Dec 11 | Jan 25 |
| Fall | by Dec 3 | Dec 3 | Next spring |
Spinach in nearby zones
Further reading on spinach
- Cold frame gardening by zone
How a cold frame keeps spinach producing into winter, and when to sow it.
- Winter sowing guide
Sowing spinach outdoors in jugs in late winter, with no lights.
- Last frost date and what to plant before it
Why spinach can go out before your last frost, and how far before.
Other crops in Zone 10b
Frequently asked questions
When should I start spinach in Zone 10b?
Direct sow outdoors around Dec 11.
Can I direct sow spinach in Zone 10b?
Yes, direct sow around Dec 11.
Can I plant spinach in the fall in Zone 10b?
Yes. Plant spinach between November 19 and December 3 in Zone 10b, roughly 6 to 4 weeks before the average first frost, so it roots before the ground freezes.
Will spinach survive frost in Zone 10b?
Spinach is a hardy crop and keeps going roughly 28 days past the first light frost in Zone 10b. A row cover or a straw mulch buys more.
How many plantings of spinach fit in a Zone 10b season?
About 5. Zone 10b averages 350 frost-free days and spinach needs roughly 45 days plus a couple of weeks of turnaround, so sowing every 30 days keeps a supply coming.