When should I plant basil in ZIP 98101?

In ZIP 98101, the main basil target is around Mar 30, based on the representative Seattle frost station and USDA zone 9a.

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

In ZIP 98101, plant basil around Mar 30.

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

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

Read the method

Season map

Basil windows by month

JanFebMarAprMayJunJulAugSepOctNovDec

Start indoors

Feb 13

Direct sow

Mar 30

Transplant

Mar 30

Harvest

Jun 3

Frost watch

Sep 16

Reminder workflow

Every date has a next action

Start basil indoorsFeb 13

Last frost windowMar 20

Direct sow basilMar 30

Transplant basilMar 30

First basil harvest windowJun 3

Last basil sowing targetSep 16

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	10-12 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

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

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 20. A conservative last sowing target is around Sep 16.