When should I plant cilantro in ZIP 97204?

In ZIP 97204, the main cilantro target is around Mar 18, based on the representative Portland frost station and USDA zone 9a.

When should I start cilantro seeds indoors in 97204?

Cilantro is usually direct-sown for ZIP 97204. Use the Mar 18 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 97204 planting calendar

When to plant cilantro in Portland, OR - Zone 9a

Q: When is the first frost in Portland?

Portland (ZIP 97204) has an average first fall frost around Nov 10, leaving about 223 frost-free days.

In ZIP 97204, plant cilantro around Mar 18; this uses the Portland frost station, USDA zone 9a, and cilantro timing rules.

Your Portland calendar has a 223-day estimated frost-free season. This estimate uses the representative Portland frost station, USDA zone 9a, and cilantro timing rules.

Source: portland-intl 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.

USDA zone 9a Portland frost station Oregon State University Extension Updated 2026-06-28

Read the method

Answer first

When to start cilantro seeds indoors in Portland

In ZIP 97204, cilantro is usually direct-sown around Mar 18 instead of started indoors.

Cilantro is normally direct-sown in Portland. Use around Mar 18 as the outdoor planting window for ZIP 97204.

Seed starting schedule

Cilantro dates for Portland, OR

Step	Date	How to use it
Direct Sow	March 18, 2026	Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Portland?

Portland (ZIP 97204) has an average last spring frost around Apr 1.

First frost

When is the first frost in Portland?

The average first fall frost is around Nov 10, giving about 223 frost-free days.

Season map

Cilantro windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Direct sow

Mar 18

Harvest

May 2

Frost watch

Sep 26

Reminder workflow

Every date has a next action

Direct sow cilantroMar 18

Last frost windowApr 1

First cilantro harvest windowMay 2

Last cilantro sowing targetSep 26

Signal	Value	Why it matters
Last frost estimate	April 1, 2026	Warm-season transplant risk starts falling after this window.
First frost estimate	November 10, 2026	Fall planting counts backward from this date.
Season length	223 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

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

Oregon 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 10. A conservative last sowing target is around Sep 26.