When to plant swiss chard in Tokyo

Swiss chard is cold-hardy, so every date keys off Tokyo's frost dates of Mar 28.
Step 1 · Sow
Start seeds indoors
Feb 28 – Mar 21
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Mar 14 – Apr 4
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
May 3 – May 13
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Sep 13 – Sep 27
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Nov 9 – Nov 19
Maturity window for the second sowing.
Window
Days to maturity
50 – 60 d
Tokyo's 258-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
MAR 28
DEC 11

Common questions

When can I sow swiss chard outdoors in Tokyo?

Direct-sow around mid March (Mar 14–Apr 4) in Tokyo, based on its local frost dates. Confidence 45%.

When will swiss chard be ready to harvest in Tokyo?

Expect to harvest from around early May (May 3–May 13) in Tokyo, based on its local frost dates. Confidence 40%.

When should I start swiss chard seeds indoors in Tokyo?

Start seeds indoors around late February (Feb 28–Mar 21) in Tokyo, based on its local frost dates. Confidence 43%.

When can I transplant swiss chard outdoors in Tokyo?

Transplant outdoors around mid March (Mar 14–Apr 4) in Tokyo, based on its local frost dates. Confidence 45%.

Can I plant swiss chard in autumn in Tokyo?

Yes — Tokyo supports a second, autumn sowing of swiss chard around mid September (Sep 13–Sep 27), timed to mature before the first fall frost.

How long is the growing season in Tokyo?

Tokyo has roughly 258 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 45/100 · Curated · based on NASA POWER (modeled) 1991–2020 · frost dates are probabilities, not guarantees.