When to plant leek in Portland
Leek is cold-hardy, so every date keys off Portland's frost dates of Mar 1.
Step 1 · Sow
Start seeds indoors
Dec 21 – Jan 11
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Feb 15 – Mar 8
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
May 26 – Jun 15
Picking runs until conditions turn against the crop.
Window
Days to maturity
100 – 120 d
Portland's 266-day season leaves this much room.
Leek on Portland'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 1
NOV 22
Common questions
When will leek be ready to harvest in Portland?
Expect to harvest from around late May (May 26–Jun 15) in Portland, based on its local frost dates. Confidence 79%.
When should I start leek seeds indoors in Portland?
Start seeds indoors around late December (Dec 21–Jan 11) in Portland, based on its local frost dates. Confidence 84%.
When can I transplant leek outdoors in Portland?
Transplant outdoors around mid February (Feb 15–Mar 8) in Portland, based on its local frost dates. Confidence 88%.
How long is the growing season in Portland?
Portland has roughly 266 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 Portland's frost dates.
Confidence 88/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.