When to plant onion in Jacksonville
Onion is cold-hardy, so every date keys off Jacksonville's frost dates of Feb 9.
Step 1 · Sow
Start seeds indoors
Dec 1 – Dec 22
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Jan 20 – Feb 10
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Apr 20 – May 10
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
Jacksonville's 311-day season leaves this much room.
Onion on Jacksonville'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
FEB 9
DEC 17
Common questions
When will onion be ready to harvest in Jacksonville?
Expect to harvest from around mid April (Apr 20–May 10) in Jacksonville, based on its local frost dates. Confidence 76%.
When should I start onion seeds indoors in Jacksonville?
Start seeds indoors around early December (Dec 1–Dec 22) in Jacksonville, based on its local frost dates. Confidence 80%.
When can I transplant onion outdoors in Jacksonville?
Transplant outdoors around mid January (Jan 20–Feb 10) in Jacksonville, based on its local frost dates. Confidence 81%.
How long is the growing season in Jacksonville?
Jacksonville has roughly 311 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 Jacksonville's frost dates.
Confidence 84/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.