When to plant onion in Greensboro
Onion is cold-hardy, so every date keys off Greensboro's frost dates of Apr 4.
Step 1 · Sow
Start seeds indoors
Jan 24 – Feb 14
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Mar 25 – Apr 15
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 23 – Jul 13
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
Greensboro's 220-day season leaves this much room.
Onion on Greensboro'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 4
NOV 5
Common questions
When will onion be ready to harvest in Greensboro?
Expect to harvest from around late June (Jun 23–Jul 13) in Greensboro, based on its local frost dates. Confidence 79%.
When should I start onion seeds indoors in Greensboro?
Start seeds indoors around late January (Jan 24–Feb 14) in Greensboro, based on its local frost dates. Confidence 84%.
When can I transplant onion outdoors in Greensboro?
Transplant outdoors around late March (Mar 25–Apr 15) in Greensboro, based on its local frost dates. Confidence 85%.
How long is the growing season in Greensboro?
Greensboro has roughly 220 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 Greensboro's frost dates.
Confidence 88/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.