When to plant radish in Denver
Radish is cold-hardy, so every date keys off Denver's frost dates of May 4.
Step 1 · Sow
Direct sow outdoors
Apr 6 – Apr 27
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
May 1 – May 6
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Aug 20 – Sep 3
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Sep 21 – Sep 26
Maturity window for the second sowing.
Window
Days to maturity
25 – 30 d
Denver's 157-day season leaves this much room.
Radish on Denver'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
MAY 4
OCT 10
Common questions
When can I sow radish outdoors in Denver?
Direct-sow around early April (Apr 6–Apr 27) in Denver, based on its local frost dates. Confidence 85%.
When will radish be ready to harvest in Denver?
Expect to harvest from around early May (May 1–May 6) in Denver, based on its local frost dates. Confidence 76%.
Can I plant radish in autumn in Denver?
Yes — Denver supports a second, autumn sowing of radish around mid August (Aug 20–Sep 3), timed to mature before the first fall frost.
How long is the growing season in Denver?
Denver has roughly 157 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 Denver's frost dates.
Confidence 85/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.