When to plant summer squash / zucchini in Riverside
Summer squash / Zucchini is frost-tender, so every date keys off Riverside's last spring frost of Feb 16.
Step 1 · Sow
Start seeds indoors
Mar 19 – Apr 9
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 9 – Apr 30
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
May 24 – Jun 8
Picking runs until conditions turn against the crop.
Window
Days to maturity
45 – 60 d
Riverside's 293-day season leaves this much room.
Summer squash / Zucchini on Riverside'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
FEB 16
DEC 6
Common questions
When can I sow summer squash / zucchini outdoors in Riverside?
Direct-sow around early April (Apr 9–Apr 30) in Riverside, based on its local frost dates. Confidence 78%.
When will summer squash / zucchini be ready to harvest in Riverside?
Expect to harvest from around late May (May 24–Jun 8) in Riverside, based on its local frost dates. Confidence 70%.
When should I start summer squash / zucchini seeds indoors in Riverside?
Start seeds indoors around mid March (Mar 19–Apr 9) in Riverside, based on its local frost dates. Confidence 74%.
When can I transplant summer squash / zucchini outdoors in Riverside?
Transplant outdoors around early April (Apr 9–Apr 30) in Riverside, based on its local frost dates. Confidence 78%.
How long is the growing season in Riverside?
Riverside has roughly 293 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 Riverside's frost dates.
Confidence 78/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.