When to plant lettuce in Sapporo

Lettuce is cold-hardy, so every date keys off Sapporo's frost dates of May 12.
Step 1 · Sow
Start seeds indoors
Apr 14 – May 5
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 27 – May 18
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 11 – Jun 26
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Jul 25 – Aug 8
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Sep 15 – Sep 30
Maturity window for the second sowing.
Window
Days to maturity
45 – 60 d
Sapporo's 166-day season leaves this much room.
Lettuce on Sapporo'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
MAY 12
OCT 20

Common questions

When can I sow lettuce outdoors in Sapporo?

Direct-sow around late April (Apr 27–May 18) in Sapporo, based on its local frost dates. Confidence 44%.

When will lettuce be ready to harvest in Sapporo?

Expect to harvest from around mid June (Jun 11–Jun 26) in Sapporo, based on its local frost dates. Confidence 40%.

When should I start lettuce seeds indoors in Sapporo?

Start seeds indoors around mid April (Apr 14–May 5) in Sapporo, based on its local frost dates. Confidence 43%.

When can I transplant lettuce outdoors in Sapporo?

Transplant outdoors around late April (Apr 27–May 18) in Sapporo, based on its local frost dates. Confidence 44%.

Can I plant lettuce in autumn in Sapporo?

Yes — Sapporo supports a second, autumn sowing of lettuce around late July (Jul 25–Aug 8), timed to mature before the first fall frost.

How long is the growing season in Sapporo?

Sapporo has roughly 166 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 Sapporo's frost dates.

Confidence 45/100 · Curated · based on NASA POWER (modeled) 1991–2020 · frost dates are probabilities, not guarantees.