When to plant sweet potato in Billings
Sweet potato is frost-tender, so every date keys off Billings's last spring frost of May 8.
Step 1 · Plant
Transplant outdoors
Jun 15 – Jul 6
Once frost risk has passed and nights stay mild.
Step 2 · Harvest
Harvest window
Sep 13 – Oct 13
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 120 d
Billings's 150-day season leaves this much room.
Sweet potato on Billings'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 8
OCT 4
Common questions
When will sweet potato be ready to harvest in Billings?
Expect to harvest from around mid September (Sep 13–Oct 13) in Billings, based on its local frost dates. Confidence 81%.
When can I transplant sweet potato outdoors in Billings?
Transplant outdoors around mid June (Jun 15–Jul 6) in Billings, based on its local frost dates. Confidence 87%.
How long is the growing season in Billings?
Billings has roughly 150 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 Billings's frost dates.
Confidence 90/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.