When to plant sweet potato in London
Sweet potato is frost-tender, so every date keys off London's last spring frost of Apr 10.
Step 1 · Plant
Transplant outdoors
May 1 – May 22
Once frost risk has passed and nights stay mild.
Step 2 · Harvest
Harvest window
Jul 30 – Aug 29
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 120 d
London's 209-day season leaves this much room.
Sweet potato on London'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 10
NOV 5
Common questions
When will sweet potato be ready to harvest in London?
Expect to harvest from around late July (Jul 30–Aug 29) in London, based on its local frost dates. Confidence 79%.
When can I transplant sweet potato outdoors in London?
Transplant outdoors around early May (May 1–May 22) in London, based on its local frost dates. Confidence 88%.
How long is the growing season in London?
London has roughly 209 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 London's frost dates.
Confidence 88/100 · NOAA GHCN-Daily · 1991–2020 normals · frost dates are probabilities, not guarantees.