Growing spinach in zone 10b
(Zone 10b = an average winter low of 35°F to 40°F.)
In USDA zone 10b, the typical last spring frost is January 16 and the first fall frost is January 15. Here is when to plant spinach against those dates.
This near-frost-free pattern wraps across New Year. The listed first fall frost falls in the following calendar year.
Typical timing
Zone 10b planting schedule
Evidence trail
How these dates are built
Sprout applies the cited planting offsets to the typical zone 10b frost anchors. The result is a planning baseline for the zone, not a local weather forecast.
- USDA Plant Hardiness Zone Map, 2023USDA Agricultural Research Service / Oregon State University PRISM Group. Supports the USDA hardiness-zone band.
- U.S. Climate Normals 1991-2020NOAA National Centers for Environmental Information. Supports the median spring and fall freeze dates.
- How to Grow Spinach in Your GardenUtah State University Extension. Supports indoor seed-starting timing (derived), outdoor transplant timing (normalized), direct-sowing timing (direct), and fall direct-sowing timing (derived).
Method note
All fields. Transplants near the last frost-free date, seed 3-4 weeks earlier, 5-6 weeks to grow transplants (sow-indoors re-expressed against last frost), spacing 3 inches in rows 12 inches, depth 1/2 inch, water 1-2 inches/week (lower bound stored), aphids/slugs/flea beetles, summer bolting. Fall window converted from 'plant 50-75 days before maturity, maturity 1-2 weeks after first fall frost' at 7 days/week. USU also notes spinach overwinters under mulch if it has 4-5 true leaves late in the year.
These are zone 10b averages
Computed from 262 ZIP codes in zone 10b. Your town's frost dates vary; enter your ZIP for dates built on your nearest weather station.
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Put these dates to work
The plant profile covers spacing, light, water, soil, and source-backed timing details. The growing guide covers preparation, care, and harvest technique.