When to plant lavender in Seattle, Washington
March 13 – March 27
Transplant outdoors · typical Seattle yearClimate basis: NOAA station Seattle Boeing Fld, WA (USW00024234), 5 mi (8 km) from downtown Seattle (ZCTA 98104 centroid), elevation 20 ft, on the 1991–2020 climate normals. Transplant lavender outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (March 13). One year in ten still freezes after April 1.
The Seattle year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to Apr 1
Every method, with its sources
Transplant outdoors
Mar 13 – Mar 27Utah State University Extension instructs transplanting after the last spring frost, a point rule encoded per policy as a 14-day span opening at the last-frost date; no reconciliation was needed because this is the entry's only source. Anchored to the median last spring freeze (Mar 13). Utah State University Extension
Start seeds indoors
Not calculatedThe cited extension guides do not time an indoor seed-starting window for this crop.
Direct-sow outdoors
Not calculatedUtah State University Extension advises against direct seeding, stating that the germination rate is low and that seeding to transplanting takes between 100 and 200 days.
Fall planting
Not calculatedNo source-backed fall planting rule exists for this crop in the registry, so no fall window is calculated.
These windows describe typical years (1991–2020 climate normals), not this year's forecast. Freezes happen outside them — especially in frost pockets, valleys, and urban edges. Watch the forecast before committing tender plants.
Crop rule sources (1)
- Utah State University Extension: How to Grow English Lavender in Your Garden (accessed 2026-07-25)"Transplant new plants after the last spring frost."