When to plant onion in Melbourne
Onion is cold-hardy, so every date keys off Melbourne's frost dates of Aug 28.
Step 1 · Sow
Start seeds indoors
Jun 19 – Jul 10
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Aug 7 – Aug 28
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Nov 5 – Nov 25
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
Melbourne's 270-day season leaves this much room.
Onion on Melbourne'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
AUG 28
MAY 25
Common questions
When will onion be ready to harvest in Melbourne?
Expect to harvest from around early November (Nov 5–Nov 25) in Melbourne, based on its local frost dates. Confidence 77%.
When should I start onion seeds indoors in Melbourne?
Start seeds indoors around mid June (Jun 19–Jul 10) in Melbourne, based on its local frost dates. Confidence 82%.
When can I transplant onion outdoors in Melbourne?
Transplant outdoors around early August (Aug 7–Aug 28) in Melbourne, based on its local frost dates. Confidence 86%.
How long is the growing season in Melbourne?
Melbourne has roughly 270 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 Melbourne's frost dates.
Confidence 86/100 · NOAA GHCN-Daily · 1991–2020 normals · frost dates are probabilities, not guarantees.