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ZIP 21201 planting calendar

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

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

Reviewed by GrowZone Editorial. Calculated from the baltimore-inner-harbor frost station and USDA zone 7b, last updated 2026-06-28.

In the Baltimore area, basil timing follows the Baltimore frost window, so the local ZIP date can differ from a broad zone-only calendar.

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

When to start basil seeds indoors in Baltimore

In ZIP 21201, start basil seeds indoors around Mar 11, about 35 days before the Apr 15 last-frost estimate.

Start basil seeds indoors in Baltimore around Mar 11, about 35 days before the Apr 15 last-frost estimate.

Seed starting schedule

Basil dates for Baltimore, MD

StepDateHow to use it
Start IndoorsMarch 11, 2026Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsApril 25, 2026Move hardened-off seedlings outside after the frost-risk window.
Direct SowApril 25, 2026Sow 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

Basil windows by month

JanFebMarAprMayJunJulAugSepOctNovDec
Start indoors
Mar 11
Direct sow
Apr 25
Transplant
Apr 25
Harvest
Jun 29
Frost watch
Sep 1

Reminder workflow

Every date has a next action

Start basil indoorsMar 11
Last frost windowApr 15
Direct sow basilApr 25
Transplant basilApr 25
First basil harvest windowJun 29
Last basil sowing targetSep 1
SignalValueWhy it matters
Last frost estimateApril 15, 2026Warm-season transplant risk starts falling after this window.
First frost estimateNovember 5, 2026Fall planting counts backward from this date.
Season length204 daysLonger seasons can support succession crops.
Spacing10-12 inAirflow and root space affect yield.
Soil temperature65 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

Basil timing notes

Pinch the growing tips early for fuller plants. Basil prefers full sun, 10-12 in spacing, and soil near 65 F+.

For fall, count backward from Nov 5. A conservative last sowing target is around Sep 1.