Frost dates for Troy, ID
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
May 15
typical year
Safe to plant
June 2
frost is over in 9 of 10 years
First fall frost
September 21
typical year
Growing season
126 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | Apr 17 – May 1 | – |
| Spinach | – | Apr 3 – 24 | Jul 27 – Aug 10 |
| Lettuce | – | Apr 17 – May 8 | Jul 27 – Aug 10 |
| Radishes | – | Apr 17 – May 29 | Aug 10 – 24 |
| Onions | – | Apr 17 – May 1 | – |
| Potatoes | – | Apr 24 – May 8 | – |
| Carrots | – | Apr 24 – May 15 | Jun 29 – Jul 13 |
| Beets | – | Apr 17 – May 1 | Jul 13 – 27 |
| Kale | Mar 6 – 20 | Apr 17 – May 1 | Jul 13 – 27 |
| Broccoli | Mar 6 – 20 | May 1 – 15 | Jul 13 – 27 |
| Cabbage | Feb 20 – Mar 6 | Apr 17 – May 1 | Jul 13 – 27 |
| Garlic | – | – | Aug 10 – 31 |
| Warm-season crops | |||
| Tomatoes | Apr 7 – 21 | Jun 2 – 16 | – |
| Peppers | Mar 31 – Apr 14 | Jun 9 – 23 | – |
| Cucumbers | – | Jun 2 – 23 | – |
| Zucchini | – | Jun 2 – 30 | – |
| Pumpkins | – | Jun 2 – 23 | – |
| Green beans | – | Jun 2 – Jul 13 | – |
| Sweet corn | – | Jun 2 – 30 | – |
| Basil | Apr 28 – May 12 | Jun 9 – 16 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | June 2 | May 15 | April 30 |
| Fall frost before | August 31 | September 21 | October 7 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around April 28 (May 13 in a late year), and the first one in fall around October 5.
Towns that use these dates
This is the nearest NOAA station with frost records for 7 towns.
Palouse, WA, Troy, Potlatch, Garfield, WA, Deary, Onaway, Farmington, WA
Where these dates come from
NOAA weather station POTLATCH 3 NNE, ID US (USC00107301), 1991–2020 climate normals. It's the nearest station for 9 zip codes, all within 16 miles:
83824, 83834, 83855, 83857, 83870, 83871, 83872, 99128, 99130
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.