When to plant watercress in Montana
Montana spans USDA zones 4b–5b, so the right time to plant watercress shifts by weeks across the state. The window to sow seed directly outdoors runs from about April 20 in Billings to May 30 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 20 – May 18 |
| Missoula | 5b | May 10 | October 1 | April 26 – May 24 |
| Great Falls | 4b | May 6 | October 1 | April 22 – May 20 |
| Bozeman | 5a | May 26 | September 22 | May 12 – June 9 |
| Butte-Silver Bow | 5a | June 13 | September 5 | May 30 – June 27 |
| Helena | 5a | May 9 | September 30 | April 25 – May 23 |
| Kalispell | 5b | May 31 | September 10 | May 17 – June 14 |
| Belgrade | 5a | May 26 | September 16 | May 12 – June 9 |
Watercress in Montana: FAQ
When can I plant watercress in Montana?
Across Montana, the time to direct-sow watercress spans roughly April 20 in Billings to May 30 in Butte-Silver Bow, each following that city's local frost dates.
Does the watercress planting date vary across Montana?
Yes. Montana publishes 8 cities with their own frost dates, so the right watercress 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 watercress take to grow in Montana?
Watercress takes about 45–60 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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