When to plant mizuna in Montana
Montana spans USDA zones 4b–5b, so the right time to plant mizuna shifts by weeks across the state. The window to sow seed directly 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 | Direct sow |
|---|---|---|---|---|
| Billings | 5a | May 4 | October 7 | April 6 – May 18 |
| Missoula | 5b | May 10 | October 1 | April 12 – May 24 |
| Great Falls | 4b | May 6 | October 1 | April 8 – May 20 |
| Bozeman | 5a | May 26 | September 22 | April 28 – June 9 |
| Butte-Silver Bow | 5a | June 13 | September 5 | May 16 – June 27 |
| Helena | 5a | May 9 | September 30 | April 11 – May 23 |
| Kalispell | 5b | May 31 | September 10 | May 3 – June 14 |
| Belgrade | 5a | May 26 | September 16 | April 28 – June 9 |
Mizuna in Montana: FAQ
When can I plant mizuna in Montana?
Across Montana, the time to direct-sow mizuna spans roughly April 6 in Billings to May 16 in Butte-Silver Bow, each following that city's local frost dates.
Does the mizuna planting date vary across Montana?
Yes. Montana publishes 8 cities with their own frost dates, so the right mizuna 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 mizuna take to grow in Montana?
Mizuna takes about 40–50 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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