Lewiston Orchards, ID planting zone & frost dates

Lewiston Orchards is in USDA hardiness zone 7b. The last spring frost usually comes around April 6 and the first fall frost around October 26, for a growing season of about 200 days.

USDA hardiness zone7bavg. extreme winter low 5°F to 10°F
Average last spring frostApril 690% chance of no frost after April 26
Average first fall frostOctober 2610% chance of frost by October 10
Growing season200 daysfrost-free days in an average year

Planting calendar for Lewiston Orchards

Dates are counted from the average last spring frost (April 6) 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.

CropWhen
TomatoesStart seeds indoors: Feb 9 – Feb 23
Transplant outdoors: Apr 13 – Apr 20
PeppersStart seeds indoors: Jan 26 – Feb 9
Transplant outdoors: Apr 20 – Apr 27
EggplantStart seeds indoors: Jan 26 – Feb 9
Transplant outdoors: Apr 20 – Apr 27
BroccoliStart seeds indoors: Jan 26 – Feb 9
Transplant outdoors: Mar 9 – Mar 23
CabbageStart seeds indoors: Jan 26 – Feb 9
Transplant outdoors: Mar 9 – Mar 23
Onions (sets)Plant outdoors: Mar 9 – Mar 23
PeasSow outdoors: Feb 23 – Mar 9
SpinachSow outdoors: Feb 23 – Mar 9
LettuceSow outdoors: Mar 9 – Mar 23
CarrotsSow outdoors: Mar 9 – Mar 23
PotatoesPlant outdoors: Mar 9 – Mar 23
BeansSow outdoors: Apr 13 – Apr 20
Sweet cornSow outdoors: Apr 13 – Apr 20
CucumbersSow outdoors: Apr 13 – Apr 20
Squash & zucchiniSow outdoors: Apr 13 – Apr 20
BasilStart seeds indoors: Feb 23 – Mar 9
Transplant outdoors: Apr 13 – Apr 20

Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 31 (8 weeks before the average first fall frost on Oct 26).

Useful for zone 7b gardens

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Frost risk in detail

90% chance50% chance10% chance
Last 32°F frost in spring is afterMar 20Apr 6Apr 26
First 32°F frost in fall is beforeNov 12Oct 26Oct 10

How to read it: in spring there is a 10% chance of a frost after April 26, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 10. A hard freeze (28°F) usually ends around March 15.

Nearby cities

All cities in Idaho → · Other zone 7b cities →

Questions

What growing zone is Lewiston Orchards, ID?

Lewiston Orchards is in USDA Plant Hardiness Zone 7b (average extreme winter low 5°F to 10°F), according to the USDA 2023 map.

When is the last frost in Lewiston Orchards?

The average last spring frost (32°F) in Lewiston Orchards is April 6. There is still a 10% chance of frost until April 26.

When can I plant tomatoes in Lewiston Orchards?

Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 13 – Apr 20. Start seeds indoors 6–8 weeks before the last frost.

Frost dates: NOAA U.S. Climate Normals 1991–2020, station Lewiston Nez Perce Co Ap, ID (USW00024149), 3.1 km (1.9 mi) from the city center, elevation 438 m, based on 28 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.