When to plant radish in San Jose
Radish is cold-hardy, so every date keys off San Jose's frost dates of Feb 12.
Step 1 · Sow
Direct sow outdoors
Dec 25 – Jan 15
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Jan 19 – Jan 24
Picking runs until conditions turn against the crop.
Step 3 · Second sowing
Autumn / second sowing
Oct 13 – Oct 27
A second window for a fall crop, timed to mature before the first frost.
Step 4 · Second harvest
Autumn crop harvest
Nov 14 – Nov 19
Maturity window for the second sowing.
Window
Days to maturity
25 – 30 d
San Jose's 294-day season leaves this much room.
Radish on San Jose'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
FEB 12
DEC 3
Common questions
When can I sow radish outdoors in San Jose?
Direct-sow around late December (Dec 25–Jan 15) in San Jose, based on its local frost dates. Confidence 80%.
When will radish be ready to harvest in San Jose?
Expect to harvest from around mid January (Jan 19–Jan 24) in San Jose, based on its local frost dates. Confidence 74%.
Can I plant radish in autumn in San Jose?
Yes — San Jose supports a second, autumn sowing of radish around mid October (Oct 13–Oct 27), timed to mature before the first fall frost.
How long is the growing season in San Jose?
San Jose has roughly 294 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 San Jose's frost dates.
Confidence 82/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.