When to plant radish in Seattle
Radish is cold-hardy, so every date keys off Seattle's frost dates of Mar 17.
Step 1 · Sow
Direct sow outdoors
Dec 26 – Jan 16
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Jan 20 – Jan 25
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Sep 23 – Oct 7
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Oct 25 – Oct 30
Maturity window for the second sowing.
Window
Days to maturity
25 – 30 d
Seattle's 237-day season leaves this much room.
Radish 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 radish outdoors in Seattle?
Direct-sow around late December (Dec 26–Jan 16) in Seattle, based on its local frost dates. Confidence 81%.
When will radish be ready to harvest in Seattle?
Expect to harvest from around mid January (Jan 20–Jan 25) in Seattle, based on its local frost dates. Confidence 75%.
Can I plant radish in autumn in Seattle?
Yes — Seattle supports a second, autumn sowing of radish around late September (Sep 23–Oct 7), 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 radish to maturity outdoors.
The rule of thumb
Sow radish 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.