When to plant basil in Cologne
Basil is frost-tender, so every date keys off Cologne's last spring frost of Apr 20.
Step 1 · Sow
Start seeds indoors
Mar 16 – Apr 6
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 27 – May 18
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 26 – Jul 26
Picking runs until conditions turn against the crop.
Window
Days to maturity
60 – 90 d
Cologne's 185-day season leaves this much room.
Basil 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 can I sow basil outdoors in Cologne?
Direct-sow around late April (Apr 27–May 18) in Cologne, based on its local frost dates. Confidence 82%.
When will basil be ready to harvest in Cologne?
Expect to harvest from around late June (Jun 26–Jul 26) in Cologne, based on its local frost dates. Confidence 74%.
When should I start basil seeds indoors in Cologne?
Start seeds indoors around mid March (Mar 16–Apr 6) in Cologne, based on its local frost dates. Confidence 78%.
When can I transplant basil outdoors in Cologne?
Transplant outdoors around late April (Apr 27–May 18) 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 basil to maturity outdoors.
The rule of thumb
Sow basil 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.