When to plant leek in Detroit
Leek is cold-hardy, so every date keys off Detroit's frost dates of Apr 15.
Step 1 · Sow
Start seeds indoors
Feb 4 – Feb 25
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 11 – May 2
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jul 20 – Aug 9
Picking runs until conditions turn against the crop.
Window
Days to maturity
100 – 120 d
Detroit's 194-day season leaves this much room.
Leek 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 leek be ready to harvest in Detroit?
Expect to harvest from around mid July (Jul 20–Aug 9) in Detroit, based on its local frost dates. Confidence 79%.
When should I start leek seeds indoors in Detroit?
Start seeds indoors around early February (Feb 4–Feb 25) in Detroit, based on its local frost dates. Confidence 84%.
When can I transplant leek outdoors in Detroit?
Transplant outdoors around mid April (Apr 11–May 2) in Detroit, based on its local frost dates. Confidence 85%.
How long is the growing season in Detroit?
Detroit has roughly 194 frost-free days, which is enough time to grow leek to maturity outdoors.
The rule of thumb
Sow leek 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.