When to plant onion in Lexington
Onion is cold-hardy, so every date keys off Lexington's frost dates of Apr 11.
Step 1 · Sow
Start seeds indoors
Jan 31 – Feb 21
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 6 – Apr 27
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jul 5 – Jul 25
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
Lexington's 196-day season leaves this much room.
Onion on Lexington'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 11
OCT 27
Common questions
When will onion be ready to harvest in Lexington?
Expect to harvest from around early July (Jul 5–Jul 25) in Lexington, based on its local frost dates. Confidence 80%.
When should I start onion seeds indoors in Lexington?
Start seeds indoors around late January (Jan 31–Feb 21) in Lexington, based on its local frost dates. Confidence 85%.
When can I transplant onion outdoors in Lexington?
Transplant outdoors around early April (Apr 6–Apr 27) in Lexington, based on its local frost dates. Confidence 86%.
How long is the growing season in Lexington?
Lexington has roughly 196 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 Lexington's frost dates.
Confidence 89/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.