When to plant sweet corn in Philadelphia
Sweet corn is frost-tender, so every date keys off Philadelphia's last spring frost of Mar 28.
Step 1 · Sow
Direct sow outdoors
Apr 30 – May 21
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Jun 29 – Aug 8
Picking runs until conditions turn against the crop.
Window
Days to maturity
60 – 100 d
Philadelphia's 234-day season leaves this much room.
Sweet corn on Philadelphia'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
MAR 28
NOV 22
Common questions
When can I sow sweet corn outdoors in Philadelphia?
Direct-sow around late April (Apr 30–May 21) in Philadelphia, based on its local frost dates. Confidence 84%.
When will sweet corn be ready to harvest in Philadelphia?
Expect to harvest from around late June (Jun 29–Aug 8) in Philadelphia, based on its local frost dates. Confidence 78%.
How long is the growing season in Philadelphia?
Philadelphia has roughly 234 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 Philadelphia's frost dates.
Confidence 87/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.