When to plant sweet potato in Philadelphia
Sweet potato is frost-tender, so every date keys off Philadelphia's last spring frost of Mar 28.
Step 1 · Plant
Transplant outdoors
May 21 – Jun 11
Once frost risk has passed and nights stay mild.
Step 2 · Harvest
Harvest window
Aug 19 – Sep 18
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 120 d
Philadelphia's 234-day season leaves this much room.
Sweet potato 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
MAR 28
NOV 22
Common questions
When will sweet potato be ready to harvest in Philadelphia?
Expect to harvest from around mid August (Aug 19–Sep 18) in Philadelphia, based on its local frost dates. Confidence 78%.
When can I transplant sweet potato outdoors in Philadelphia?
Transplant outdoors around late May (May 21–Jun 11) in Philadelphia, based on its local frost dates. Confidence 84%.
How long is the growing season in Philadelphia?
Philadelphia has roughly 234 frost-free days, which is enough time to grow sweet potato to maturity outdoors.
The rule of thumb
Sow sweet potato 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.