When to plant basil in Glasgow
Basil is frost-tender, so every date keys off Glasgow's last spring frost of May 5.
Step 1 · Sow
Start seeds indoors
Mar 31 – Apr 21
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
May 12 – Jun 2
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jul 11 – Aug 10
Picking runs until conditions turn against the crop.
Window
Days to maturity
60 – 90 d
Glasgow's 163-day season leaves this much room.
Basil on Glasgow'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 5
OCT 15
Common questions
When can I sow basil outdoors in Glasgow?
Direct-sow around mid May (May 12–Jun 2) in Glasgow, based on its local frost dates. Confidence 70%.
When will basil be ready to harvest in Glasgow?
Expect to harvest from around mid July (Jul 11–Aug 10) in Glasgow, based on its local frost dates. Confidence 63%.
When should I start basil seeds indoors in Glasgow?
Start seeds indoors around late March (Mar 31–Apr 21) in Glasgow, based on its local frost dates. Confidence 67%.
When can I transplant basil outdoors in Glasgow?
Transplant outdoors around mid May (May 12–Jun 2) in Glasgow, based on its local frost dates. Confidence 70%.
How long is the growing season in Glasgow?
Glasgow has roughly 163 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 Glasgow's frost dates.
Confidence 70/100 · NASA POWER (modeled) · 1991–2020 · frost dates are probabilities, not guarantees.