When to plant summer squash / zucchini in Modesto
Summer squash / Zucchini is frost-tender, so every date keys off Modesto's last spring frost of Jan 27.
Step 1 · Sow
Start seeds indoors
Feb 10 – Mar 3
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 22 – May 13
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 6 – Jun 21
Picking runs until conditions turn against the crop.
Window
Days to maturity
45 – 60 d
Modesto's 310-day season leaves this much room.
Summer squash / Zucchini on Modesto'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
JAN 27
DEC 3
Common questions
When can I sow summer squash / zucchini outdoors in Modesto?
Direct-sow around late April (Apr 22–May 13) in Modesto, based on its local frost dates. Confidence 84%.
When will summer squash / zucchini be ready to harvest in Modesto?
Expect to harvest from around early June (Jun 6–Jun 21) in Modesto, based on its local frost dates. Confidence 78%.
When should I start summer squash / zucchini seeds indoors in Modesto?
Start seeds indoors around early February (Feb 10–Mar 3) in Modesto, based on its local frost dates. Confidence 83%.
When can I transplant summer squash / zucchini outdoors in Modesto?
Transplant outdoors around late April (Apr 22–May 13) in Modesto, based on its local frost dates. Confidence 84%.
How long is the growing season in Modesto?
Modesto has roughly 310 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 Modesto's frost dates.
Confidence 87/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.