When to plant onion in Overland Park
Onion is cold-hardy, so every date keys off Overland Park's frost dates of Apr 8.
Step 1 · Sow
Start seeds indoors
Jan 28 – Feb 18
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
Overland Park's 200-day season leaves this much room.
Onion on Overland Park'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 8
OCT 27
Common questions
When will onion be ready to harvest in Overland Park?
Expect to harvest from around early July (Jul 5–Jul 25) in Overland Park, based on its local frost dates. Confidence 76%.
When should I start onion seeds indoors in Overland Park?
Start seeds indoors around late January (Jan 28–Feb 18) in Overland Park, based on its local frost dates. Confidence 80%.
When can I transplant onion outdoors in Overland Park?
Transplant outdoors around early April (Apr 6–Apr 27) in Overland Park, based on its local frost dates. Confidence 81%.
How long is the growing season in Overland Park?
Overland Park has roughly 200 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 Overland Park's frost dates.
Confidence 84/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.