When to plant summer squash / zucchini in Bristol
Summer squash / Zucchini is frost-tender, so every date keys off Bristol's last spring frost of Apr 18.
Step 1 · Sow
Start seeds indoors
Apr 4 – Apr 25
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 25 – May 16
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 9 – Jun 24
Picking runs until conditions turn against the crop.
Window
Days to maturity
45 – 60 d
Bristol's 197-day season leaves this much room.
Summer squash / Zucchini on Bristol'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 18
NOV 1
Common questions
When can I sow summer squash / zucchini outdoors in Bristol?
Direct-sow around late April (Apr 25–May 16) in Bristol, based on its local frost dates. Confidence 82%.
When will summer squash / zucchini be ready to harvest in Bristol?
Expect to harvest from around early June (Jun 9–Jun 24) in Bristol, based on its local frost dates. Confidence 74%.
When should I start summer squash / zucchini seeds indoors in Bristol?
Start seeds indoors around early April (Apr 4–Apr 25) in Bristol, based on its local frost dates. Confidence 78%.
When can I transplant summer squash / zucchini outdoors in Bristol?
Transplant outdoors around late April (Apr 25–May 16) in Bristol, based on its local frost dates. Confidence 82%.
How long is the growing season in Bristol?
Bristol has roughly 197 frost-free days, which is enough time to grow summer squash / zucchini to maturity outdoors.
The rule of thumb
Sow summer squash / zucchini 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 Bristol's frost dates.
Confidence 82/100 · NOAA GHCN-Daily · 1991–2020 normals · frost dates are probabilities, not guarantees.