When to plant onion in Mobile
Onion is cold-hardy, so every date keys off Mobile's frost dates of Feb 20.
Step 1 · Sow
Start seeds indoors
Dec 12 – Jan 2
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Dec 26 – Jan 16
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Mar 26 – Apr 15
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
Mobile's 287-day season leaves this much room.
Onion on Mobile'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
FEB 20
NOV 29
Common questions
When will onion be ready to harvest in Mobile?
Expect to harvest from around late March (Mar 26–Apr 15) in Mobile, based on its local frost dates. Confidence 76%.
When should I start onion seeds indoors in Mobile?
Start seeds indoors around mid December (Dec 12–Jan 2) in Mobile, based on its local frost dates. Confidence 81%.
When can I transplant onion outdoors in Mobile?
Transplant outdoors around late December (Dec 26–Jan 16) in Mobile, based on its local frost dates. Confidence 82%.
How long is the growing season in Mobile?
Mobile has roughly 287 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 Mobile's frost dates.
Confidence 85/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.