When to plant spinach in Detroit
Spinach is cold-hardy, so every date keys off Detroit's frost dates of Apr 15.
Step 1 · Sow
Direct sow outdoors
Mar 31 – Apr 21
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
May 10 – May 20
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Aug 21 – Sep 4
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Oct 7 – Oct 17
Maturity window for the second sowing.
Window
Days to maturity
40 – 50 d
Detroit's 194-day season leaves this much room.
Spinach on Detroit'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
APR 15
OCT 31
Common questions
When can I sow spinach outdoors in Detroit?
Direct-sow around late March (Mar 31–Apr 21) in Detroit, based on its local frost dates. Confidence 85%.
When will spinach be ready to harvest in Detroit?
Expect to harvest from around early May (May 10–May 20) in Detroit, based on its local frost dates. Confidence 79%.
Can I plant spinach in autumn in Detroit?
Yes — Detroit supports a second, autumn sowing of spinach around late August (Aug 21–Sep 4), timed to mature before the first fall frost.
How long is the growing season in Detroit?
Detroit has roughly 194 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 Detroit's frost dates.
Confidence 88/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.