When to plant lavender in Denver, Colorado
April 30 – May 14
Transplant outdoors · typical Denver yearClimate basis: NOAA station Denver Water Dept, CO (USC00052223), 2 mi (3 km) from downtown Denver (ZCTA 80202 centroid), elevation 5228 ft, on the 1991–2020 climate normals. Transplant lavender outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (April 30). One year in ten still freezes after May 13.
The Denver year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to May 13
Every method, with its sources
Transplant outdoors
Apr 30 – May 14Utah 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 (Apr 30). 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."