When to plant sweet corn in Tokyo
Sweet corn is frost-tender, so every date keys off Tokyo's last spring frost of Mar 25.
Step 1 · Sow
Direct sow outdoors
Apr 1 – Apr 22
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
May 31 – Jul 10
Picking runs until conditions turn against the crop.
Window
Days to maturity
60 – 100 d
Tokyo's 255-day season leaves this much room.
Sweet corn 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
HARVEST
MAR 25
DEC 5
Common questions
When can I sow sweet corn outdoors in Tokyo?
Direct-sow around early April (Apr 1–Apr 22) in Tokyo, based on its local frost dates. Confidence 88%.
When will sweet corn be ready to harvest in Tokyo?
Expect to harvest from around late May (May 31–Jul 10) in Tokyo, based on its local frost dates. Confidence 79%.
How long is the growing season in Tokyo?
Tokyo has roughly 255 frost-free days, which is enough time to grow sweet corn to maturity outdoors.
The rule of thumb
Sow sweet corn 6–8 weeks before your last spring frost; plant out 2–3 weeks after it. 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.