When to plant onion in Fukuoka
Onion is cold-hardy, so every date keys off Fukuoka's frost dates of Apr 4.
Step 1 · Sow
Start seeds indoors
Jan 24 – Feb 14
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 7 – Apr 28
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jul 6 – Jul 26
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
Fukuoka's 239-day season leaves this much room.
Onion on Fukuoka'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
APR 4
NOV 30
Common questions
When will onion be ready to harvest in Fukuoka?
Expect to harvest from around early July (Jul 6–Jul 26) in Fukuoka, based on its local frost dates. Confidence 40%.
When should I start onion seeds indoors in Fukuoka?
Start seeds indoors around late January (Jan 24–Feb 14) in Fukuoka, based on its local frost dates. Confidence 43%.
When can I transplant onion outdoors in Fukuoka?
Transplant outdoors around early April (Apr 7–Apr 28) in Fukuoka, based on its local frost dates. Confidence 44%.
How long is the growing season in Fukuoka?
Fukuoka has roughly 239 frost-free days, which is enough time to grow onion to maturity outdoors.
The rule of thumb
Sow onion 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 Fukuoka's frost dates.
Confidence 45/100 · Curated · based on NASA POWER (modeled) 1991–2020 · frost dates are probabilities, not guarantees.