When should I plant cilantro in ZIP 98101?

In ZIP 98101, the main cilantro target is around Mar 6, based on the representative Seattle frost station and USDA zone 9a.

When should I start cilantro seeds indoors in 98101?

Cilantro is usually direct-sown for ZIP 98101. Use the Mar 6 planting window instead of starting it indoors.

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 98101 planting calendar

When to plant cilantro in Seattle, WA - Zone 9a

Q: When is the first frost in Seattle?

Seattle (ZIP 98101) has an average first fall frost around Nov 20, leaving about 245 frost-free days.

In ZIP 98101, plant cilantro around Mar 6; this uses the Seattle frost station, USDA zone 9a, and cilantro timing rules.

Your Seattle calendar has a 245-day estimated frost-free season. This estimate uses the representative Seattle frost station, USDA zone 9a, and cilantro timing rules.

Source: seattle-tacoma frost station, USDA zone 9a, 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 seattle-tacoma frost station and USDA zone 9a, last updated 2026-06-28.

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

USDA zone 9a Seattle frost station Washington State University Extension Updated 2026-06-28

Read the method

Answer first

When to start cilantro seeds indoors in Seattle

In ZIP 98101, cilantro is usually direct-sown around Mar 6 instead of started indoors.

Cilantro is normally direct-sown in Seattle. Use around Mar 6 as the outdoor planting window for ZIP 98101.

Seed starting schedule

Cilantro dates for Seattle, WA

Step	Date	How to use it
Direct Sow	March 6, 2026	Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Seattle?

Seattle (ZIP 98101) has an average last spring frost around Mar 20.

First frost

When is the first frost in Seattle?

The average first fall frost is around Nov 20, giving about 245 frost-free days.

Season map

Cilantro windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Direct sow

Mar 6

Harvest

Apr 20

Frost watch

Oct 6

Reminder workflow

Every date has a next action

Direct sow cilantroMar 6

Last frost windowMar 20

First cilantro harvest windowApr 20

Last cilantro sowing targetOct 6

Signal	Value	Why it matters
Last frost estimate	March 20, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	November 20, 2026	Fall planting counts backward from this date.
Season length	245 days	Longer seasons can support succession crops.
Spacing	4-6 in	Airflow and root space affect yield.
Soil temperature	45 F+	Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

Seattle frost history and USDA zone 9a shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

Washington State University 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

Cilantro timing notes

Sow small batches often because cilantro bolts in heat. Cilantro prefers sun to part shade, 4-6 in spacing, and soil near 45 F+.

For fall, count backward from Nov 20. A conservative last sowing target is around Oct 6.