When to plant swiss chard in Sapporo
Swiss chard is cold-hardy, so every date keys off Sapporo's frost dates of May 5.
Step 1 · Sow
Start seeds indoors
Apr 7 – Apr 28
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 21 – May 12
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 10 – Jun 20
Picking runs until conditions turn against the crop.
Window
Days to maturity
50 – 60 d
Sapporo's 173-day season leaves this much room.
Swiss chard 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 5
OCT 25
Common questions
When can I sow swiss chard outdoors in Sapporo?
Direct-sow around late April (Apr 21–May 12) in Sapporo, based on its local frost dates. Confidence 84%.
When will swiss chard be ready to harvest in Sapporo?
Expect to harvest from around early June (Jun 10–Jun 20) in Sapporo, based on its local frost dates. Confidence 76%.
When should I start swiss chard seeds indoors in Sapporo?
Start seeds indoors around early April (Apr 7–Apr 28) in Sapporo, based on its local frost dates. Confidence 80%.
When can I transplant swiss chard outdoors in Sapporo?
Transplant outdoors around late April (Apr 21–May 12) in Sapporo, based on its local frost dates. Confidence 84%.
How long is the growing season in Sapporo?
Sapporo has roughly 173 frost-free days, which is enough time to grow swiss chard to maturity outdoors.
The rule of thumb
Sow swiss chard 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 84/100 · NOAA GHCN-Daily · 1991–2020 normals · frost dates are probabilities, not guarantees.