When to plant horseradish in Montana
Montana spans USDA zones 4b–5b, so the right time to plant horseradish shifts by weeks across the state. The window to transplant seedlings outdoors runs from about April 6 in Billings to May 16 in Butte-Silver Bow — below are local dates for 8 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Transplant out |
|---|---|---|---|---|
| Billings | 5a | May 4 | October 7 | April 6 – April 20 |
| Missoula | 5b | May 10 | October 1 | April 12 – April 26 |
| Great Falls | 4b | May 6 | October 1 | April 8 – April 22 |
| Bozeman | 5a | May 26 | September 22 | April 28 – May 12 |
| Butte-Silver Bow | 5a | June 13 | September 5 | May 16 – May 30 |
| Helena | 5a | May 9 | September 30 | April 11 – April 25 |
| Kalispell | 5b | May 31 | September 10 | May 3 – May 17 |
| Belgrade | 5a | May 26 | September 16 | April 28 – May 12 |
Horseradish in Montana: FAQ
When can I plant horseradish in Montana?
Across Montana, the time to transplant horseradish spans roughly April 6 in Billings to May 16 in Butte-Silver Bow, each following that city's local frost dates.
Does the horseradish planting date vary across Montana?
Yes. Montana publishes 8 cities with their own frost dates, so the right horseradish planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.
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