When to plant onion in Moreno Valley
Onion is cold-hardy, so every date keys off Moreno Valley's frost dates of Feb 23.
Step 1 · Sow
Start seeds indoors
Dec 15 – Jan 5
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Dec 26 – Jan 16
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Mar 26 – Apr 15
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
Moreno Valley's 284-day season leaves this much room.
Onion on Moreno Valley'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
FEB 23
DEC 9
Common questions
When will onion be ready to harvest in Moreno Valley?
Expect to harvest from around late March (Mar 26–Apr 15) in Moreno Valley, based on its local frost dates. Confidence 74%.
When should I start onion seeds indoors in Moreno Valley?
Start seeds indoors around mid December (Dec 15–Jan 5) in Moreno Valley, based on its local frost dates. Confidence 78%.
When can I transplant onion outdoors in Moreno Valley?
Transplant outdoors around late December (Dec 26–Jan 16) in Moreno Valley, based on its local frost dates. Confidence 80%.
How long is the growing season in Moreno Valley?
Moreno Valley has roughly 284 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 Moreno Valley's frost dates.
Confidence 82/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.