When to plant onion in Strasbourg
Onion is cold-hardy, so every date keys off Strasbourg's frost dates of Apr 25.
Step 1 · Sow
Start seeds indoors
Feb 14 – Mar 7
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 4 – Apr 25
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jul 3 – Jul 23
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
Strasbourg's 172-day season leaves this much room.
Onion on Strasbourg'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 25
OCT 14
Common questions
When will onion be ready to harvest in Strasbourg?
Expect to harvest from around early July (Jul 3–Jul 23) in Strasbourg, based on its local frost dates. Confidence 63%.
When should I start onion seeds indoors in Strasbourg?
Start seeds indoors around mid February (Feb 14–Mar 7) in Strasbourg, based on its local frost dates. Confidence 67%.
When can I transplant onion outdoors in Strasbourg?
Transplant outdoors around early April (Apr 4–Apr 25) in Strasbourg, based on its local frost dates. Confidence 70%.
How long is the growing season in Strasbourg?
Strasbourg has roughly 172 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 Strasbourg's frost dates.
Confidence 70/100 · NASA POWER (modeled) · 1991–2020 · frost dates are probabilities, not guarantees.