Missoula, MT · zone 5a · ~144 frost-free days
When to plant in Missoula: frost dates and zone 5a.
In Missoula, the typical last spring frost lands around May 10 and the first fall frost around Oct 1, giving you about 144 frost-free days. Cool-season crops go out before the last frost; warm-season crops wait until after it.
The 2026 windows
Sow dates for Missoula, keyed to your frost.
| Crop | Start indoors | Spring sow / set out | Fall sow |
|---|---|---|---|
| Tomato, slicing | Apr 5 to May 25 | May 17 to Jul 6 | — |
| Lettuce, leaf | — | Apr 2 to May 17 | Jul 18 to Sep 16 |
| Carrot | — | Apr 2 to May 5 | Jul 6 to Aug 1 |
| Bush Bean | — | May 10 to Jun 30 | — |
| Cucumber, slicing | — | May 17 to Jul 15 | — |
| Pepper, bell | Apr 14 to May 28 | May 26 to Jul 9 | — |
| Kale | Feb 19 to Mar 19 | Apr 2 to Apr 30 | Jul 1 to Aug 16 |
| Spinach | — | Mar 19 to Apr 30 | Jul 18 to Sep 5 |
Missoula sits in Zone 5a, but two gardens in the same city can be a week or two apart. The planner works from your ZIP code's frost dates, not the zone, so the dates land right for your block, not the metro average.
Build your Missoula garden plan.
Tell the free planner what you want to eat and who you're feeding. It returns plant counts, spacing, and frost-safe sow dates for ZIP 59801 in about 60 seconds.
Missoula planting questions
What planting zone is Missoula, MT?+
Missoula is in USDA hardiness zone 5a. Growing zone, gardening zone, and planting zone all mean the same thing: the USDA number, 5a here. It tells you what survives winter, not when to plant. Frost dates set your planting time, and the free planner uses your exact ZIP code's frost dates, which can differ by weeks across one metro.
When is the last frost date in Missoula?+
The typical last spring frost in Missoula, MT is around May 10. That is an average from local history, not a guarantee, so tender crops like tomatoes and peppers are safer with a week of buffer after it.
When is the first frost date in Missoula?+
The typical first fall frost in Missoula, MT arrives around Oct 1, closing a growing season of roughly 144 frost-free days. Count backward from it to find the last date a fall crop can still finish.
What can I plant now in Missoula?+
It depends on the date. Cool-season crops like lettuce, kale, and spinach go out weeks before the last frost; warm-season crops like tomatoes and peppers wait until after May 10. The table above shows each crop's window; the free planner turns your ZIP into an exact, dated calendar.