When to plant onion in Cleveland
Onion is cold-hardy, so every date keys off Cleveland's frost dates of Apr 5.
Step 1 · Sow
Start seeds indoors
Jan 25 – Feb 15
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 22 – May 13
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jul 21 – Aug 10
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
Cleveland's 227-day season leaves this much room.
Onion on Cleveland'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 5
NOV 16
Common questions
When will onion be ready to harvest in Cleveland?
Expect to harvest from around late July (Jul 21–Aug 10) in Cleveland, based on its local frost dates. Confidence 76%.
When should I start onion seeds indoors in Cleveland?
Start seeds indoors around late January (Jan 25–Feb 15) in Cleveland, based on its local frost dates. Confidence 80%.
When can I transplant onion outdoors in Cleveland?
Transplant outdoors around late April (Apr 22–May 13) in Cleveland, based on its local frost dates. Confidence 81%.
How long is the growing season in Cleveland?
Cleveland has roughly 227 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 Cleveland's frost dates.
Confidence 84/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.