When to plant leek in Tokyo
Leek is cold-hardy, so every date keys off Tokyo's frost dates of Mar 25.
Step 1 · Sow
Start seeds indoors
Jan 14 – Feb 4
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
Jun 19 – Jul 9
Picking runs until conditions turn against the crop.
Window
Days to maturity
100 – 120 d
Tokyo's 255-day season leaves this much room.
Leek 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 will leek be ready to harvest in Tokyo?
Expect to harvest from around mid June (Jun 19–Jul 9) in Tokyo, based on its local frost dates. Confidence 79%.
When should I start leek seeds indoors in Tokyo?
Start seeds indoors around mid January (Jan 14–Feb 4) in Tokyo, based on its local frost dates. Confidence 84%.
When can I transplant leek 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 leek to maturity outdoors.
The rule of thumb
Sow leek 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.