When to plant winter squash in Montana
Montana spans USDA zones 4b–5b, so the right time to plant winter squash shifts by weeks across the state. The window to sow seed directly outdoors runs from about May 11 in Billings to June 20 in Butte-Silver Bow — below are local dates for 8 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Direct sow |
|---|---|---|---|---|
| Billings | 5a | May 4 | October 7 | May 11 – May 25 |
| Missoula | 5b | May 10 | October 1 | May 17 – May 31 |
| Great Falls | 4b | May 6 | October 1 | May 13 – May 27 |
| Bozeman | 5a | May 26 | September 22 | June 2 – June 16 |
| Butte-Silver Bow | 5a | June 13 | September 5 | June 20 – July 4 |
| Helena | 5a | May 9 | September 30 | May 16 – May 30 |
| Kalispell | 5b | May 31 | September 10 | June 7 – June 21 |
| Belgrade | 5a | May 26 | September 16 | June 2 – June 16 |
Winter Squash in Montana: FAQ
When can I plant winter squash in Montana?
Across Montana, the time to direct-sow winter squash spans roughly May 11 in Billings to June 20 in Butte-Silver Bow, each following that city's local frost dates.
Does the winter squash planting date vary across Montana?
Yes. Montana publishes 8 cities with their own frost dates, so the right winter squash 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 winter squash take to grow in Montana?
Winter Squash takes about 85–110 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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