When to plant tarragon in Billings, Montana
May 10 – May 24
Transplant outdoors · typical Billings yearClimate basis: NOAA station Billings Wtp, MT (USC00240802), 13 mi (21 km) from downtown Billings (ZCTA 59101 centroid), elevation 3097 ft, on the 1991–2020 climate normals. Transplant tarragon outdoors from approximately the dates above, anchored to the median last spring 32°F freeze (May 10). One year in ten still freezes after May 24.
The Billings year
- indoors under lights
- in the garden
- frost-free season
- 1-in-10 years still freeze to May 24
Every method, with its sources
Transplant outdoors
May 10 – May 24USU Extension says to transplant French tarragon in the spring after the last frost so the tender young shoots survive, a point rule that opens a two-week planting span at the last spring freeze. Anchored to the median last spring freeze (May 10). Utah State University Extension · Virginia Cooperative Extension, Virginia Tech
Start seeds indoors
Not calculatedThe cited extension guides do not time an indoor seed-starting window for this crop.
Direct-sow outdoors
Not calculatedThe cited extension guides do not time direct sowing for this crop.
Fall planting
Not calculatedNo source-backed fall planting rule exists for this crop in the registry, so no fall window is calculated.
Variety assumption: Assumes French tarragon, which Virginia Cooperative Extension says can only be propagated asexually — seed-grown plants are the flavourless Russian type — so no seed-sowing window is given.
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 (2)
- Utah State University Extension: How to Grow French Tarragon in Your Garden (accessed 2026-07-25)"Transplant French tarragon in the spring, after the last frost, to ensure the survival of tender young shoots."
- Virginia Cooperative Extension, Virginia Tech: Herb Culture and Use (Publication 426-420) (accessed 2026-07-25)"In addition, many culinary herbs, such as tarragon, can only be propagated asexually; seed-grown plants lack the oils that give them flavor."