When to plant spinach in Duluth
Spinach is cold-hardy, so every date keys off Duluth's frost dates of May 10.
Step 1 · Sow
Direct sow outdoors
Apr 22 – May 13
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Jun 1 – Jun 11
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Jul 28 – Aug 11
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Sep 13 – Sep 23
Maturity window for the second sowing.
Window
Days to maturity
40 – 50 d
Duluth's 150-day season leaves this much room.
Spinach on Duluth'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
MAY 10
OCT 7
Common questions
When can I sow spinach outdoors in Duluth?
Direct-sow around late April (Apr 22–May 13) in Duluth, based on its local frost dates. Confidence 84%.
When will spinach be ready to harvest in Duluth?
Expect to harvest from around early June (Jun 1–Jun 11) in Duluth, based on its local frost dates. Confidence 78%.
Can I plant spinach in autumn in Duluth?
Yes — Duluth supports a second, autumn sowing of spinach around late July (Jul 28–Aug 11), timed to mature before the first fall frost.
How long is the growing season in Duluth?
Duluth has roughly 150 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 Duluth's frost dates.
Confidence 87/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.