When should I plant zucchini in ZIP 21201?

In ZIP 21201, the main zucchini target is around Apr 25, based on the representative Baltimore frost station and USDA zone 7b.

When should I start zucchini seeds indoors in 21201?

Start zucchini seeds indoors in ZIP 21201 around Mar 25, about 21 days before the Apr 15 last-frost estimate.

Is this a guaranteed planting date?

No. GrowZone uses frost-date estimates, hardiness zones, and crop timing rules for planning. Local microclimates and current weather can shift the right date.

ZIP 21201 planting calendar

When to plant zucchini in Baltimore, MD - Zone 7b

Q: When is the first frost in Baltimore?

Baltimore (ZIP 21201) has an average first fall frost around Nov 5, leaving about 204 frost-free days.

In ZIP 21201, plant zucchini around Apr 25; this uses the Baltimore frost station, USDA zone 7b, and zucchini timing rules.

Your Baltimore calendar has a 204-day estimated frost-free season. This estimate uses the representative Baltimore frost station, USDA zone 7b, and zucchini timing rules.

Source: baltimore-inner-harbor frost station, USDA zone 7b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.

USDA zone 7b Baltimore frost station University of Maryland Extension Updated 2026-06-28

Read the method

Answer first

When to start zucchini seeds indoors in Baltimore

In ZIP 21201, start zucchini seeds indoors around Mar 25, about 21 days before the Apr 15 last-frost estimate.

Start zucchini seeds indoors in Baltimore around Mar 25, about 21 days before the Apr 15 last-frost estimate.

Seed starting schedule

Zucchini dates for Baltimore, MD

Step	Date	How to use it
Start Indoors	March 25, 2026	Start seeds under lights or in a bright indoor seed-starting space.
Transplant Outdoors	April 25, 2026	Move hardened-off seedlings outside after the frost-risk window.
Direct Sow	April 25, 2026	Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Baltimore?

Baltimore (ZIP 21201) has an average last spring frost around Apr 15.

First frost

When is the first frost in Baltimore?

The average first fall frost is around Nov 5, giving about 204 frost-free days.

Season map

Zucchini windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Start indoors

Mar 25

Direct sow

Apr 25

Transplant

Apr 25

Harvest

Jun 19

Frost watch

Sep 11

Reminder workflow

Every date has a next action

Start zucchini indoorsMar 25

Last frost windowApr 15

Direct sow zucchiniApr 25

Transplant zucchiniApr 25

First zucchini harvest windowJun 19

Last zucchini sowing targetSep 11

Signal	Value	Why it matters
Last frost estimate	April 15, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	November 5, 2026	Fall planting counts backward from this date.
Season length	204 days	Longer seasons can support succession crops.
Spacing	24-36 in	Airflow and root space affect yield.
Soil temperature	65 F+	Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

Baltimore frost history and USDA zone 7b shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

University of Maryland Extension is the kind of local source to verify against when a crop is expensive, weather is unusual, or your yard has a cold pocket.

Crop note

Zucchini timing notes

One or two healthy plants can feed a household. Zucchini prefers full sun, 24-36 in spacing, and soil near 65 F+.

For fall, count backward from Nov 5. A conservative last sowing target is around Sep 11.