When to plant spinach in San Bernardino
Spinach is cold-hardy, so every date keys off San Bernardino's frost dates of Feb 23.
Step 1 · Sow
Direct sow outdoors
Dec 26 – Jan 16
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Feb 4 – Feb 14
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Sep 29 – Oct 13
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Nov 15 – Nov 25
Maturity window for the second sowing.
Window
Days to maturity
40 – 50 d
San Bernardino's 284-day season leaves this much room.
Spinach on San Bernardino'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 23
DEC 9
Common questions
When can I sow spinach outdoors in San Bernardino?
Direct-sow around late December (Dec 26–Jan 16) in San Bernardino, based on its local frost dates. Confidence 76%.
When will spinach be ready to harvest in San Bernardino?
Expect to harvest from around early February (Feb 4–Feb 14) in San Bernardino, based on its local frost dates. Confidence 70%.
Can I plant spinach in autumn in San Bernardino?
Yes — San Bernardino supports a second, autumn sowing of spinach around late September (Sep 29–Oct 13), timed to mature before the first fall frost.
How long is the growing season in San Bernardino?
San Bernardino has roughly 284 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 Bernardino's frost dates.
Confidence 78/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.