When to plant brussels sprouts in Montana
Montana spans USDA zones 4b–5b, so the right time to plant brussels sprouts shifts by weeks across the state. The window to transplant seedlings outdoors runs from about May 4 in Billings to June 13 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 | May 4 – May 18 |
| Missoula | 5b | May 10 | October 1 | May 10 – May 24 |
| Great Falls | 4b | May 6 | October 1 | May 6 – May 20 |
| Bozeman | 5a | May 26 | September 22 | May 26 – June 9 |
| Butte-Silver Bow | 5a | June 13 | September 5 | June 13 – June 27 |
| Helena | 5a | May 9 | September 30 | May 9 – May 23 |
| Kalispell | 5b | May 31 | September 10 | May 31 – June 14 |
| Belgrade | 5a | May 26 | September 16 | May 26 – June 9 |
Brussels Sprouts in Montana: FAQ
When can I plant brussels sprouts in Montana?
Across Montana, the time to transplant brussels sprouts spans roughly May 4 in Billings to June 13 in Butte-Silver Bow, each following that city's local frost dates.
Does the brussels sprouts planting date vary across Montana?
Yes. Montana publishes 8 cities with their own frost dates, so the right brussels sprouts planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.
How long does brussels sprouts take to grow in Montana?
Brussels Sprouts takes about 90–110 days to reach harvest once planted — check that this fits inside your city's frost-free season on its place page.
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