Newberg, OR planting zone & frost dates

Newberg is in USDA hardiness zone 8b. The last spring frost usually comes around March 21 and the first fall frost around November 22, for a growing season of about 241 days.

USDA hardiness zone8bavg. extreme winter low 15°F to 20°F

Average last spring frostMarch 2190% chance of no frost after April 19

Average first fall frostNovember 2210% chance of frost by November 4

Growing season241 daysfrost-free days in an average year

Planting calendar for Newberg

Dates are counted from the average last spring frost (March 21) 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: Jan 24 – Feb 7 Transplant outdoors: Mar 28 – Apr 4
Peppers	Start seeds indoors: Jan 10 – Jan 24 Transplant outdoors: Apr 4 – Apr 11
Eggplant	Start seeds indoors: Jan 10 – Jan 24 Transplant outdoors: Apr 4 – Apr 11
Broccoli	Start seeds indoors: Jan 10 – Jan 24 Transplant outdoors: Feb 21 – Mar 7
Cabbage	Start seeds indoors: Jan 10 – Jan 24 Transplant outdoors: Feb 21 – Mar 7
Onions (sets)	Plant outdoors: Feb 21 – Mar 7
Peas	Sow outdoors: Feb 7 – Feb 21
Spinach	Sow outdoors: Feb 7 – Feb 21
Lettuce	Sow outdoors: Feb 21 – Mar 7
Carrots	Sow outdoors: Feb 21 – Mar 7
Potatoes	Plant outdoors: Feb 21 – Mar 7
Beans	Sow outdoors: Mar 28 – Apr 4
Sweet corn	Sow outdoors: Mar 28 – Apr 4
Cucumbers	Sow outdoors: Mar 28 – Apr 4
Squash & zucchini	Sow outdoors: Mar 28 – Apr 4
Basil	Start seeds indoors: Feb 7 – Feb 21 Transplant outdoors: Mar 28 – Apr 4

Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 27 (8 weeks before the average first fall frost on Nov 22).

Useful for zone 8b 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

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Frost risk in detail

	90% chance	50% chance	10% chance
Last 32°F frost in spring is after	Feb 23	Mar 21	Apr 19
First 32°F frost in fall is before	Dec 12	Nov 22	Nov 4

How to read it: in spring there is a 10% chance of a frost after April 19, so that is a safe date for tender plants. In fall there is a 10% chance of frost before November 4. A hard freeze (28°F) usually ends around February 15.

Hardiness zone by ZIP code in Newberg

97132 zone 8b

Nearby cities

Sherwood zone 8b, last frost Mar 21
Woodburn zone 8b, last frost Mar 16
Wilsonville zone 8b, last frost Mar 18
Aloha zone 9a, last frost Feb 11
Hillsboro zone 8b, last frost Apr 16
Tualatin zone 9a, last frost Apr 1
Cornelius zone 8b, last frost Apr 16
Tigard zone 9a, last frost Apr 1

All cities in Oregon → · Other zone 8b cities →

Questions

What growing zone is Newberg, OR?

Newberg is in USDA Plant Hardiness Zone 8b (average extreme winter low 15°F to 20°F), according to the USDA 2023 map.

When is the last frost in Newberg?

The average last spring frost (32°F) in Newberg is March 21. There is still a 10% chance of frost until April 19.

When can I plant tomatoes in Newberg?

Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Mar 28 – Apr 4. Start seeds indoors 6–8 weeks before the last frost.

Frost dates: NOAA U.S. Climate Normals 1991–2020, station Rex 1 S, OR (USC00357127), 4.7 km (2.9 mi) from the city center, elevation 157 m, based on 10 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.