When to plant radish in Calgary
Radish is cold-hardy, so every date keys off Calgary's frost dates of May 22.
Step 1 · Sow
Direct sow outdoors
Apr 30 – May 21
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
May 25 – May 30
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Jul 30 – Aug 13
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Aug 31 – Sep 5
Maturity window for the second sowing.
Window
Days to maturity
25 – 30 d
Calgary's 120-day season leaves this much room.
Radish on Calgary'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 22
SEP 19
Common questions
When can I sow radish outdoors in Calgary?
Direct-sow around late April (Apr 30–May 21) in Calgary, based on its local frost dates. Confidence 80%.
When will radish be ready to harvest in Calgary?
Expect to harvest from around late May (May 25–May 30) in Calgary, based on its local frost dates. Confidence 74%.
Can I plant radish in autumn in Calgary?
Yes — Calgary supports a second, autumn sowing of radish around late July (Jul 30–Aug 13), timed to mature before the first fall frost.
How long is the growing season in Calgary?
Calgary has roughly 120 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 Calgary's frost dates.
Confidence 82/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.