Post Falls, ID planting zone & frost dates
Post Falls is in USDA hardiness zone 6b. The last spring frost usually comes around April 22 and the first fall frost around October 18, for a growing season of about 179 days.
Planting calendar for Post Falls
Dates are counted from the average last spring frost (April 22) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Feb 25 – Mar 11 Transplant outdoors: Apr 29 – May 6 |
| Peppers | Start seeds indoors: Feb 11 – Feb 25 Transplant outdoors: May 6 – May 13 |
| Eggplant | Start seeds indoors: Feb 11 – Feb 25 Transplant outdoors: May 6 – May 13 |
| Broccoli | Start seeds indoors: Feb 11 – Feb 25 Transplant outdoors: Mar 25 – Apr 8 |
| Cabbage | Start seeds indoors: Feb 11 – Feb 25 Transplant outdoors: Mar 25 – Apr 8 |
| Onions (sets) | Plant outdoors: Mar 25 – Apr 8 |
| Peas | Sow outdoors: Mar 11 – Mar 25 |
| Spinach | Sow outdoors: Mar 11 – Mar 25 |
| Lettuce | Sow outdoors: Mar 25 – Apr 8 |
| Carrots | Sow outdoors: Mar 25 – Apr 8 |
| Potatoes | Plant outdoors: Mar 25 – Apr 8 |
| Beans | Sow outdoors: Apr 29 – May 6 |
| Sweet corn | Sow outdoors: Apr 29 – May 6 |
| Cucumbers | Sow outdoors: Apr 29 – May 6 |
| Squash & zucchini | Sow outdoors: Apr 29 – May 6 |
| Basil | Start seeds indoors: Mar 11 – Mar 25 Transplant outdoors: Apr 29 – May 6 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 23 (8 weeks before the average first fall frost on Oct 18).
Useful for zone 6b gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Cold frame / mini greenhouse — adds weeks to a short season
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 4 | Apr 22 | May 6 |
| First 32°F frost in fall is before | Nov 5 | Oct 18 | Oct 4 |
How to read it: in spring there is a 10% chance of a frost after May 6, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 4. A hard freeze (28°F) usually ends around April 1.
Hardiness zone by ZIP code in Post Falls
- 83854 zone 6b
- 83877 zone 6b
Nearby cities
- Hayden zone 6b, last frost Apr 22
- Coeur d'Alene zone 7a, last frost Apr 22
- Moscow zone 6b, last frost Apr 29
- Lewiston zone 7a, last frost Apr 6
- Lewiston Orchards zone 7b, last frost Apr 6
- Eagle Foothills zone 7a, last frost Apr 30
- Caldwell zone 7a, last frost Apr 23
- Eagle zone 7a, last frost Apr 24
Questions
What growing zone is Post Falls, ID?
Post Falls is in USDA Plant Hardiness Zone 6b (average extreme winter low -5°F to 0°F), according to the USDA 2023 map.
When is the last frost in Post Falls?
The average last spring frost (32°F) in Post Falls is April 22. There is still a 10% chance of frost until May 6.
When can I plant tomatoes in Post Falls?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 29 – May 6. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Coeur D'Alene, ID (USC00101956), 12.3 km (7.6 mi) from the city center, elevation 650 m, based on 24 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.