When to plant swiss chard in Tokyo
Swiss chard is cold-hardy, so every date keys off Tokyo's frost dates of Mar 25.
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
Mar 11 – Apr 1
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Apr 30 – May 10
Picking runs until conditions turn against the crop.
Window
Days to maturity
50 – 60 d
Tokyo's 255-day season leaves this much room.
Swiss chard on Tokyo'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
MAR 25
DEC 5
Common questions
When can I sow swiss chard outdoors in Tokyo?
Direct-sow around mid March (Mar 11–Apr 1) in Tokyo, based on its local frost dates. Confidence 88%.
When will swiss chard be ready to harvest in Tokyo?
Expect to harvest from around late April (Apr 30–May 10) in Tokyo, based on its local frost dates. Confidence 79%.
When should I start swiss chard seeds indoors in Tokyo?
Start seeds indoors around late February (Feb 25–Mar 18) in Tokyo, based on its local frost dates. Confidence 84%.
When can I transplant swiss chard outdoors in Tokyo?
Transplant outdoors around mid March (Mar 11–Apr 1) in Tokyo, based on its local frost dates. Confidence 88%.
How long is the growing season in Tokyo?
Tokyo has roughly 255 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 Tokyo's frost dates.
Confidence 88/100 · NOAA GHCN-Daily · 1991–2020 normals · frost dates are probabilities, not guarantees.