When to plant sweet potato in San Jose
Sweet potato is frost-tender, so every date keys off San Jose's last spring frost of Feb 12.
Step 1 · Plant
Transplant outdoors
Jun 8 – Jun 29
Once frost risk has passed and nights stay mild.
Step 2 · Harvest
Harvest window
Sep 6 – Oct 6
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 120 d
San Jose's 294-day season leaves this much room.
Sweet potato 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 will sweet potato be ready to harvest in San Jose?
Expect to harvest from around early September (Sep 6–Oct 6) in San Jose, based on its local frost dates. Confidence 74%.
When can I transplant sweet potato outdoors in San Jose?
Transplant outdoors around early June (Jun 8–Jun 29) in San Jose, based on its local frost dates. Confidence 80%.
How long is the growing season in San Jose?
San Jose has roughly 294 frost-free days, which is enough time to grow sweet potato to maturity outdoors.
The rule of thumb
Sow sweet potato 6–8 weeks before your last spring frost; plant out 2–3 weeks after it. 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.