When to plant spinach in San Jose
Spinach is cold-hardy, so every date keys off San Jose's frost dates of Feb 12.
Step 1 · Sow
Direct sow outdoors
Dec 25 – Jan 15
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Feb 3 – Feb 13
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Sep 23 – Oct 7
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Nov 9 – Nov 19
Maturity window for the second sowing.
Window
Days to maturity
40 – 50 d
San Jose's 294-day season leaves this much room.
Spinach on San Jose's growing year
Frost-bounded season with crops mapped onto the 12-month axis.
Frost risk Growing Harvest
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
FROST
FEB 12
DEC 3
Common questions
When can I sow spinach outdoors in San Jose?
Direct-sow around late December (Dec 25–Jan 15) in San Jose, based on its local frost dates. Confidence 80%.
When will spinach be ready to harvest in San Jose?
Expect to harvest from around early February (Feb 3–Feb 13) in San Jose, based on its local frost dates. Confidence 74%.
Can I plant spinach in autumn in San Jose?
Yes — San Jose supports a second, autumn sowing of spinach around late September (Sep 23–Oct 7), timed to mature before the first fall frost.
How long is the growing season in San Jose?
San Jose has roughly 294 frost-free days, which is enough time to grow spinach to maturity outdoors.
The rule of thumb
Sow spinach as soon as the soil is workable — it tolerates cool weather and light frost. Every date on this page is derived from that rule and San Jose's frost dates.
Confidence 82/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.