When to plant spinach in St. Louis
Spinach is cold-hardy, so every date keys off St. Louis's frost dates of Mar 30.
Step 1 · Sow
Direct sow outdoors
Feb 28 – Mar 21
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Apr 9 – Apr 19
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Aug 26 – Sep 9
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Oct 12 – Oct 22
Maturity window for the second sowing.
Window
Days to maturity
40 – 50 d
St. Louis's 218-day season leaves this much room.
Spinach on St. Louis'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
FROST
MAR 30
NOV 5
Common questions
When can I sow spinach outdoors in St. Louis?
Direct-sow around late February (Feb 28–Mar 21) in St. Louis, based on its local frost dates. Confidence 81%.
When will spinach be ready to harvest in St. Louis?
Expect to harvest from around early April (Apr 9–Apr 19) in St. Louis, based on its local frost dates. Confidence 76%.
Can I plant spinach in autumn in St. Louis?
Yes — St. Louis supports a second, autumn sowing of spinach around late August (Aug 26–Sep 9), timed to mature before the first fall frost.
How long is the growing season in St. Louis?
St. Louis has roughly 218 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 St. Louis's frost dates.
Confidence 84/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.