When to plant onion in El Paso
Onion is cold-hardy, so every date keys off El Paso's frost dates of Mar 6.
Step 1 · Sow
Start seeds indoors
Dec 26 – Jan 16
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Feb 18 – Mar 11
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
May 19 – Jun 8
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
El Paso's 252-day season leaves this much room.
Onion on El Paso'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 6
NOV 17
Common questions
When will onion be ready to harvest in El Paso?
Expect to harvest from around mid May (May 19–Jun 8) in El Paso, based on its local frost dates. Confidence 78%.
When should I start onion seeds indoors in El Paso?
Start seeds indoors around late December (Dec 26–Jan 16) in El Paso, based on its local frost dates. Confidence 83%.
When can I transplant onion outdoors in El Paso?
Transplant outdoors around mid February (Feb 18–Mar 11) in El Paso, based on its local frost dates. Confidence 84%.
How long is the growing season in El Paso?
El Paso has roughly 252 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 El Paso's frost dates.
Confidence 87/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.