When to plant onion in Fort Worth
Onion is cold-hardy, so every date keys off Fort Worth's frost dates of Mar 9.
Step 1 · Sow
Start seeds indoors
Dec 29 – Jan 19
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Feb 24 – Mar 17
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
May 25 – Jun 14
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
Fort Worth's 253-day season leaves this much room.
Onion on Fort Worth'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
MAR 9
NOV 23
Common questions
When will onion be ready to harvest in Fort Worth?
Expect to harvest from around late May (May 25–Jun 14) in Fort Worth, based on its local frost dates. Confidence 78%.
When should I start onion seeds indoors in Fort Worth?
Start seeds indoors around late December (Dec 29–Jan 19) in Fort Worth, based on its local frost dates. Confidence 83%.
When can I transplant onion outdoors in Fort Worth?
Transplant outdoors around late February (Feb 24–Mar 17) in Fort Worth, based on its local frost dates. Confidence 84%.
How long is the growing season in Fort Worth?
Fort Worth has roughly 253 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 Fort Worth's frost dates.
Confidence 87/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.