When to plant spinach in Calgary
Spinach is cold-hardy, so every date keys off Calgary's frost dates of May 22.
Step 1 · Sow
Direct sow outdoors
Apr 23 – May 14
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Jun 2 – Jun 12
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Jul 10 – Jul 24
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Aug 26 – Sep 5
Maturity window for the second sowing.
Window
Days to maturity
40 – 50 d
Calgary's 120-day season leaves this much room.
Spinach 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 spinach outdoors in Calgary?
Direct-sow around late April (Apr 23–May 14) in Calgary, based on its local frost dates. Confidence 80%.
When will spinach be ready to harvest in Calgary?
Expect to harvest from around early June (Jun 2–Jun 12) in Calgary, based on its local frost dates. Confidence 74%.
Can I plant spinach in autumn in Calgary?
Yes — Calgary supports a second, autumn sowing of spinach around early July (Jul 10–Jul 24), 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 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 Calgary's frost dates.
Confidence 82/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.