When to plant broccoli in Detroit
Broccoli is cold-hardy, so every date keys off Detroit's frost dates of Apr 15.
Step 1 · Sow
Start seeds indoors
Mar 4 – Mar 25
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 5 – Apr 26
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 4 – Jun 29
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Jul 17 – Jul 31
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Sep 22 – Oct 17
Maturity window for the second sowing.
Window
Days to maturity
60 – 85 d
Detroit's 194-day season leaves this much room.
Broccoli 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 will broccoli be ready to harvest in Detroit?
Expect to harvest from around early June (Jun 4–Jun 29) in Detroit, based on its local frost dates. Confidence 79%.
When should I start broccoli seeds indoors in Detroit?
Start seeds indoors around early March (Mar 4–Mar 25) in Detroit, based on its local frost dates. Confidence 84%.
When can I transplant broccoli outdoors in Detroit?
Transplant outdoors around early April (Apr 5–Apr 26) in Detroit, based on its local frost dates. Confidence 85%.
Can I plant broccoli in autumn in Detroit?
Yes — Detroit supports a second, autumn sowing of broccoli around mid July (Jul 17–Jul 31), 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 broccoli to maturity outdoors.
The rule of thumb
Sow broccoli 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.