When to plant broccoli in Sapporo
Broccoli is cold-hardy, so every date keys off Sapporo's frost dates of May 12.
Step 1 · Sow
Start seeds indoors
Mar 31 – Apr 21
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
May 1 – May 22
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 30 – Jul 25
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Jul 6 – Jul 20
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Sep 11 – Oct 6
Maturity window for the second sowing.
Window
Days to maturity
60 – 85 d
Sapporo's 166-day season leaves this much room.
Broccoli 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
FROST
FROST
MAY 12
OCT 20
Common questions
When will broccoli be ready to harvest in Sapporo?
Expect to harvest from around late June (Jun 30–Jul 25) in Sapporo, based on its local frost dates. Confidence 40%.
When should I start broccoli seeds indoors in Sapporo?
Start seeds indoors around late March (Mar 31–Apr 21) in Sapporo, based on its local frost dates. Confidence 43%.
When can I transplant broccoli outdoors in Sapporo?
Transplant outdoors around early May (May 1–May 22) in Sapporo, based on its local frost dates. Confidence 44%.
Can I plant broccoli in autumn in Sapporo?
Yes — Sapporo supports a second, autumn sowing of broccoli around early July (Jul 6–Jul 20), 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 broccoli to maturity outdoors.
The rule of thumb
Sow broccoli 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.