When to plant spinach in Philadelphia
Spinach is cold-hardy, so every date keys off Philadelphia's frost dates of Mar 28.
Step 1 · Sow
Direct sow outdoors
Mar 2 – Mar 23
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Apr 11 – Apr 21
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Sep 12 – Sep 26
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Oct 29 – Nov 8
Maturity window for the second sowing.
Window
Days to maturity
40 – 50 d
Philadelphia's 234-day season leaves this much room.
Spinach 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 can I sow spinach outdoors in Philadelphia?
Direct-sow around early March (Mar 2–Mar 23) in Philadelphia, based on its local frost dates. Confidence 84%.
When will spinach be ready to harvest in Philadelphia?
Expect to harvest from around mid April (Apr 11–Apr 21) in Philadelphia, based on its local frost dates. Confidence 78%.
Can I plant spinach in autumn in Philadelphia?
Yes — Philadelphia supports a second, autumn sowing of spinach around mid September (Sep 12–Sep 26), timed to mature before the first fall frost.
How long is the growing season in Philadelphia?
Philadelphia has roughly 234 frost-free days, which is enough time to grow spinach to maturity outdoors.
The rule of thumb
Sow spinach 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 Philadelphia's frost dates.
Confidence 87/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.