When to plant spinach in Calgary
Spinach is cold-hardy, so every date keys off Calgary's frost dates of May 23.
Step 1 · Sow
Direct sow outdoors
Apr 11 – May 2
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
May 21 – May 31
Picking runs until conditions turn against the crop.
Window
Days to maturity
40 – 50 d
Calgary's 115-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 23
SEP 15
Common questions
When can I sow spinach outdoors in Calgary?
Direct-sow around mid April (Apr 11–May 2) in Calgary, based on its local frost dates. Confidence 82%.
When will spinach be ready to harvest in Calgary?
Expect to harvest from around late May (May 21–May 31) in Calgary, based on its local frost dates. Confidence 74%.
How long is the growing season in Calgary?
Calgary has roughly 115 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 · NOAA GHCN-Daily · 1991–2020 normals · frost dates are probabilities, not guarantees.