When to plant sweet corn in Toronto
Sweet corn is frost-tender, so every date keys off Toronto's last spring frost of May 9.
Step 1 · Sow
Direct sow outdoors
May 16 – Jun 6
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Jul 15 – Aug 24
Picking runs until conditions turn against the crop.
Window
Days to maturity
60 – 100 d
Toronto's 150-day season leaves this much room.
Sweet corn on Toronto'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
HARVEST
MAY 9
OCT 6
Common questions
When can I sow sweet corn outdoors in Toronto?
Direct-sow around mid May (May 16–Jun 6) in Toronto, based on its local frost dates. Confidence 88%.
When will sweet corn be ready to harvest in Toronto?
Expect to harvest from around mid July (Jul 15–Aug 24) in Toronto, based on its local frost dates. Confidence 79%.
How long is the growing season in Toronto?
Toronto has roughly 150 frost-free days, which is enough time to grow sweet corn to maturity outdoors.
The rule of thumb
Sow sweet corn 6–8 weeks before your last spring frost; plant out 2–3 weeks after it. Every date on this page is derived from that rule and Toronto's frost dates.
Confidence 88/100 · NOAA GHCN-Daily · 1991–2020 normals · frost dates are probabilities, not guarantees.