Boise, ID · zone 7a · ~161 frost-free days
When to plant in Boise: frost dates and zone 7a.
In Boise, the typical last spring frost lands around May 8 and the first fall frost around Oct 16, giving you about 161 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 Boise, keyed to your frost.
| Crop | Start indoors | Spring sow / set out | Fall sow |
|---|---|---|---|
| Tomato, slicing | Apr 3 to Jun 3 | May 15 to Jul 15 | — |
| Lettuce, leaf | — | Mar 31 to May 15 | Aug 2 to Oct 1 |
| Carrot | — | Mar 31 to May 3 | Jul 21 to Aug 16 |
| Bush Bean | — | May 8 to Jun 28 | Jul 2 to Aug 4 |
| Cucumber, slicing | — | May 15 to Jul 30 | — |
| Pepper, bell | Apr 12 to Jun 3 | May 24 to Jul 15 | — |
| Kale | Feb 17 to Mar 17 | Mar 31 to Apr 28 | Jul 16 to Aug 31 |
| Spinach | — | Mar 17 to Apr 28 | Aug 2 to Sep 20 |
Boise sits in Zone 7a, 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 Boise 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 83702 in about 60 seconds.
Boise planting questions
What planting zone is Boise, ID?+
Boise is in USDA hardiness zone 7a. Growing zone, gardening zone, and planting zone all mean the same thing: the USDA number, 7a 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 Boise?+
The typical last spring frost in Boise, ID is around May 8. 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 Boise?+
The typical first fall frost in Boise, ID arrives around Oct 16, closing a growing season of roughly 161 frost-free days. Count backward from it to find the last date a fall crop can still finish.
What can I plant now in Boise?+
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 8. The table above shows each crop's window; the free planner turns your ZIP into an exact, dated calendar.