When to plant radish in St. Louis
Radish is cold-hardy, so every date keys off St. Louis's frost dates of Mar 30.
Step 1 · Sow
Direct sow outdoors
Mar 2 – Mar 23
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Mar 27 – Apr 1
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Sep 15 – Sep 29
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Oct 17 – Oct 22
Maturity window for the second sowing.
Window
Days to maturity
25 – 30 d
St. Louis's 218-day season leaves this much room.
Radish 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 radish outdoors in St. Louis?
Direct-sow around early March (Mar 2–Mar 23) in St. Louis, based on its local frost dates. Confidence 84%.
When will radish be ready to harvest in St. Louis?
Expect to harvest from around late March (Mar 27–Apr 1) in St. Louis, based on its local frost dates. Confidence 76%.
Can I plant radish in autumn in St. Louis?
Yes — St. Louis supports a second, autumn sowing of radish around mid September (Sep 15–Sep 29), 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 radish to maturity outdoors.
The rule of thumb
Sow radish 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.