When to plant broccoli in Portland
Broccoli is cold-hardy, so every date keys off Portland's frost dates of May 1.
Step 1 · Sow
Start seeds indoors
Mar 20 – Apr 10
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 17 – May 8
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 16 – Jul 11
Picking runs until conditions turn against the crop.
Step 4 · Second sowing
Autumn / second sowing
Jun 26 – Jul 10
A second window for a fall crop, timed to mature before the first frost.
Step 5 · Second harvest
Autumn crop harvest
Sep 1 – Sep 26
Maturity window for the second sowing.
Window
Days to maturity
60 – 85 d
Portland's 165-day season leaves this much room.
Broccoli 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
MAY 1
OCT 10
Common questions
When will broccoli be ready to harvest in Portland?
Expect to harvest from around mid June (Jun 16–Jul 11) in Portland, based on its local frost dates. Confidence 80%.
When should I start broccoli seeds indoors in Portland?
Start seeds indoors around mid March (Mar 20–Apr 10) in Portland, based on its local frost dates. Confidence 85%.
When can I transplant broccoli outdoors in Portland?
Transplant outdoors around mid April (Apr 17–May 8) in Portland, based on its local frost dates. Confidence 89%.
Can I plant broccoli in autumn in Portland?
Yes — Portland supports a second, autumn sowing of broccoli around late June (Jun 26–Jul 10), timed to mature before the first fall frost.
How long is the growing season in Portland?
Portland has roughly 165 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 Portland's frost dates.
Confidence 89/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.