When to plant summer squash / zucchini in Baltimore
Summer squash / Zucchini is frost-tender, so every date keys off Baltimore's last spring frost of Mar 21.
Step 1 · Sow
Start seeds indoors
Mar 17 – Apr 7
Before your last frost, on a warm windowsill or heat mat.
Step 2 · Plant
Transplant outdoors
Apr 30 – May 21
Once frost risk has passed and nights stay mild.
Step 3 · Harvest
Harvest window
Jun 14 – Jun 29
Picking runs until conditions turn against the crop.
Window
Days to maturity
45 – 60 d
Baltimore's 249-day season leaves this much room.
Summer squash / Zucchini on Baltimore'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
MAR 21
NOV 27
Common questions
When can I sow summer squash / zucchini outdoors in Baltimore?
Direct-sow around late April (Apr 30–May 21) in Baltimore, based on its local frost dates. Confidence 81%.
When will summer squash / zucchini be ready to harvest in Baltimore?
Expect to harvest from around mid June (Jun 14–Jun 29) in Baltimore, based on its local frost dates. Confidence 76%.
When should I start summer squash / zucchini seeds indoors in Baltimore?
Start seeds indoors around mid March (Mar 17–Apr 7) in Baltimore, based on its local frost dates. Confidence 80%.
When can I transplant summer squash / zucchini outdoors in Baltimore?
Transplant outdoors around late April (Apr 30–May 21) in Baltimore, based on its local frost dates. Confidence 81%.
How long is the growing season in Baltimore?
Baltimore has roughly 249 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 Baltimore's frost dates.
Confidence 84/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.