When to plant cilantro / coriander in Seattle
Cilantro / Coriander is cold-hardy, so every date keys off Seattle's frost dates of Mar 17.
Step 1 · Sow
Direct sow outdoors
Mar 3 – Mar 24
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Apr 17 – May 12
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Jul 31 – Aug 14
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Sep 21 – Oct 16
Maturity window for the second sowing.
Window
Days to maturity
45 – 70 d
Seattle's 237-day season leaves this much room.
Cilantro / Coriander on Seattle'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 17
NOV 13
Common questions
When can I sow cilantro / coriander outdoors in Seattle?
Direct-sow around early March (Mar 3–Mar 24) in Seattle, based on its local frost dates. Confidence 83%.
When will cilantro / coriander be ready to harvest in Seattle?
Expect to harvest from around mid April (Apr 17–May 12) in Seattle, based on its local frost dates. Confidence 75%.
Can I plant cilantro / coriander in autumn in Seattle?
Yes — Seattle supports a second, autumn sowing of cilantro / coriander around late July (Jul 31–Aug 14), timed to mature before the first fall frost.
How long is the growing season in Seattle?
Seattle has roughly 237 frost-free days, which is enough time to grow cilantro / coriander to maturity outdoors.
The rule of thumb
Sow cilantro / coriander 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 Seattle's frost dates.
Confidence 83/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.