When to plant leek in Ottawa
Leek is cold-hardy, so every date keys off Ottawa's frost dates of May 6.
Step 1 · Sow
Start seeds indoors
Feb 25 – Mar 18
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 22 – May 13
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jul 31 – Aug 20
Picking runs until conditions turn against the crop.
Window
Days to maturity
100 – 120 d
Ottawa's 149-day season leaves this much room.
Leek on Ottawa'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 6
OCT 2
Common questions
When will leek be ready to harvest in Ottawa?
Expect to harvest from around late July (Jul 31–Aug 20) in Ottawa, based on its local frost dates. Confidence 76%.
When should I start leek seeds indoors in Ottawa?
Start seeds indoors around late February (Feb 25–Mar 18) in Ottawa, based on its local frost dates. Confidence 80%.
When can I transplant leek outdoors in Ottawa?
Transplant outdoors around late April (Apr 22–May 13) in Ottawa, based on its local frost dates. Confidence 84%.
How long is the growing season in Ottawa?
Ottawa has roughly 149 frost-free days, which is enough time to grow leek to maturity outdoors.
The rule of thumb
Sow leek 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 Ottawa's frost dates.
Confidence 84/100 · NOAA GHCN-Daily · 1991–2020 normals · frost dates are probabilities, not guarantees.