GrowZone

ZIP 98101 planting calendar

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

In ZIP 98101, plant carrots around Feb 27; this uses the Seattle frost station, USDA zone 9a, and carrots 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 carrots 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.

In the Seattle area, carrots 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 carrots seeds indoors in Seattle

In ZIP 98101, carrots is usually direct-sown around Feb 27 instead of started indoors.

Carrots is normally direct-sown in Seattle. Use around Feb 27 as the outdoor planting window for ZIP 98101.

Seed starting schedule

Carrots dates for Seattle, WA

StepDateHow to use it
Direct SowFebruary 27, 2026Sow 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

Carrots windows by month

JanFebMarAprMayJunJulAugSepOctNovDec
Direct sow
Feb 27
Harvest
May 8
Frost watch
Sep 11

Reminder workflow

Every date has a next action

Direct sow carrotsFeb 27
Last frost windowMar 20
First carrots harvest windowMay 8
Last carrots sowing targetSep 11
SignalValueWhy it matters
Last frost estimateMarch 20, 2026Warm-season transplant risk starts falling after this window.
First frost estimateNovember 20, 2026Fall planting counts backward from this date.
Season length245 daysLonger seasons can support succession crops.
Spacing2-3 inAirflow and root space affect yield.
Soil temperature45 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

Carrots timing notes

Direct sow only; carrots dislike transplanting. Carrots prefers full sun, 2-3 in spacing, and soil near 45 F+.

For fall, count backward from Nov 20. A conservative last sowing target is around Sep 11.