When to plant sweet potato in Cologne
Sweet potato is frost-tender, so every date keys off Cologne's last spring frost of Apr 20.
Step 1 · Plant
Transplant outdoors
May 11 – Jun 1
Once frost risk has passed and nights stay mild.
Step 2 · Harvest
Harvest window
Aug 9 – Sep 8
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 120 d
Cologne's 185-day season leaves this much room.
Sweet potato on Cologne'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
APR 20
OCT 22
Common questions
When will sweet potato be ready to harvest in Cologne?
Expect to harvest from around early August (Aug 9–Sep 8) in Cologne, based on its local frost dates. Confidence 74%.
When can I transplant sweet potato outdoors in Cologne?
Transplant outdoors around mid May (May 11–Jun 1) in Cologne, based on its local frost dates. Confidence 82%.
How long is the growing season in Cologne?
Cologne has roughly 185 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 Cologne's frost dates.
Confidence 82/100 · NOAA GHCN-Daily · 1991–2020 normals · frost dates are probabilities, not guarantees.