When to plant lettuce in Ottawa

Lettuce is cold-hardy, so every date keys off Ottawa's frost dates of Apr 29.
Step 1 · Sow
Start seeds indoors
Apr 1 – Apr 22
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 19 – May 10
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 3 – Jun 18
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Jul 10 – Jul 24
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Aug 31 – Sep 15
Maturity window for the second sowing.
Window
Days to maturity
45 – 60 d
Ottawa's 161-day season leaves this much room.
Lettuce 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
APR 29
OCT 8

Common questions

When can I sow lettuce outdoors in Ottawa?

Direct-sow around mid April (Apr 19–May 10) in Ottawa, based on its local frost dates. Confidence 86%.

When will lettuce be ready to harvest in Ottawa?

Expect to harvest from around early June (Jun 3–Jun 18) in Ottawa, based on its local frost dates. Confidence 80%.

When should I start lettuce seeds indoors in Ottawa?

Start seeds indoors around early April (Apr 1–Apr 22) in Ottawa, based on its local frost dates. Confidence 85%.

When can I transplant lettuce outdoors in Ottawa?

Transplant outdoors around mid April (Apr 19–May 10) in Ottawa, based on its local frost dates. Confidence 86%.

Can I plant lettuce in autumn in Ottawa?

Yes — Ottawa supports a second, autumn sowing of lettuce around early July (Jul 10–Jul 24), timed to mature before the first fall frost.

How long is the growing season in Ottawa?

Ottawa has roughly 161 frost-free days, which is enough time to grow lettuce to maturity outdoors.

The rule of thumb

Sow lettuce 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 89/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.