What Planting Zones Are in Oregon?
Oregon spans USDA hardiness zones 5b to 9b, where the average coldest winter night ranges from −15 °F to 30 °F (−26.1 °C to −1.1 °C). Zone 8b covers the most ZIP codes, 40%, and zones 6b to 9a together cover 77% of the state.
- Zone 5b<1% · 1 ZIP
- Zone 6a6% · 27 ZIPs
- Zone 6b13% · 62 ZIPs
- Zone 7a8% · 37 ZIPs
- Zone 7b4% · 17 ZIPs
- Zone 8a3% · 14 ZIPs
- Zone 8b40% · 189 ZIPs
- Zone 9a24% · 115 ZIPs
- Zone 9b2% · 11 ZIPs
Bars show each zone's share of the 473 Oregon ZIP codes in the official 2023 USDA ZIP code table; select a zone for its temperatures and hardy plants.
What Hardiness Zone Are Oregon Cities In?
Portland is in zone 8b, Salem is in zone 8b, Eugene is in zone 8b and Gresham is in zone 9a. The table lists the zone, winter low and average frost dates for 19 Oregon cities, using the ZIP code nearest each city center.
| City | ZIP | Zone | Winter low | Last frost | First frost |
|---|---|---|---|---|---|
| Portland | 97212 | 8b | 15 °F to 20 °F | Feb 25 | Dec 1 |
| Salem | 97301 | 8b | 15 °F to 20 °F | Apr 3 | Nov 1 |
| Eugene | 97401 | 8b | 15 °F to 20 °F | Apr 11 | Oct 23 |
| Gresham | 97030 | 9a | 20 °F to 25 °F | Mar 16 | Nov 20 |
| Hillsboro | 97124 | 8b | 15 °F to 20 °F | Apr 16 | Oct 23 |
| Bend | 97702 | 6b | −5 °F to 0 °F | Jun 6 | Sep 20 |
| Beaverton | 97005 | 9a | 20 °F to 25 °F | Feb 11 | Dec 5 |
| Medford | 97504 | 8b | 15 °F to 20 °F | Apr 8 | Oct 29 |
| Corvallis | 97331 | 8b | 15 °F to 20 °F | Apr 17 | Oct 28 |
| Springfield | 97477 | 8b | 15 °F to 20 °F | Apr 11 | Oct 23 |
| Grants Pass | 97527 | 8b | 15 °F to 20 °F | Apr 8 | Oct 28 |
| McMinnville | 97128 | 8b | 15 °F to 20 °F | Apr 5 | Nov 7 |
| Woodburn | 97071 | 8b | 15 °F to 20 °F | Mar 16 | Nov 14 |
| Roseburg | 97495 | 8b | 15 °F to 20 °F | Mar 31 | Nov 5 |
| Klamath Falls | 97634 | 6b | −5 °F to 0 °F | Jun 9 | Sep 18 |
| Lebanon | 97355 | 8b | 15 °F to 20 °F | Mar 14 | Nov 18 |
| Hermiston | 97838 | 7b | 5 °F to 10 °F | Apr 27 | Oct 7 |
| Pendleton | 97801 | 7a | 0 °F to 5 °F | Apr 22 | Oct 9 |
| Burns | 97720 | 6a | −10 °F to −5 °F | Jun 11 | Sep 6 |
Zone: 2023 USDA ZIP code table for the ZIP code nearest each city's Census center point. Frost dates: 50% (median) dates from the nearest NOAA station, 1991–2020 normals. Cities: the largest Oregon places by 2024 Census population estimates, spread across the state, plus the largest place in each common zone. Large cities can span two half zones.
Which Parts of Oregon Are in Each Zone?
Zone 6a, the coldest Oregon zone with towns, covers 6% of ZIP codes around Burns, Hines and Joseph. Zone 9b, the warmest, covers 2% around Newport, Brookings and Bandon. The table lists the largest places in every zone.
| Zone | Avg. coldest night | Share of ZIPs | Largest places in this zone |
|---|---|---|---|
| Zone 5b | −15 °F to −10 °F | <1% (1) | Rural ZIP codes only |
| Zone 6a | −10 °F to −5 °F | 6% (27) | Burns, Hines, Joseph |
| Zone 6b | −5 °F to 0 °F | 13% (62) | Bend, Redmond, Klamath Falls, La Grande |
| Zone 7a | 0 °F to 5 °F | 8% (37) | Pendleton, Ontario, Madras, Milton-Freewater |
| Zone 7b | 5 °F to 10 °F | 4% (17) | Hermiston, The Dalles, Hood River, Umatilla |
| Zone 8a | 10 °F to 15 °F | 3% (14) | Ashland, Eagle Point, Shady Cove, Vernonia |
| Zone 8b | 15 °F to 20 °F | 40% (189) | Portland, Salem, Eugene, Hillsboro |
| Zone 9a | 20 °F to 25 °F | 24% (115) | Gresham, Beaverton, Tigard, Lake Oswego |
| Zone 9b | 25 °F to 30 °F | 2% (11) | Newport, Brookings, Bandon, Gold Beach |
Places: incorporated places with 1,000+ residents, assigned the zone of the ZIP code nearest their Census center point.
What Do the Hardiness Zones Mean for Oregon Gardeners?
A Oregon gardener in zone 9b sees winter lows about 40 °F milder than one in zone 5b, so a shrub or perennial that thrives in one part of the state can die in another. Choose plants rated to your own ZIP code's zone or colder.
Hardiness zones follow latitude, elevation and large bodies of water rather than state lines. Higher ground and inland valleys that trap cold air usually sit in colder half zones, while cities, coasts and large lakes moderate winter lows. Within Oregon, a plant labelled “zones 6–9” survives winter in at least 77% of ZIP codes, but plants at the edge of their range benefit from mulch and a sheltered spot. Enter a ZIP code in the USDA hardiness zone finder by ZIP code to check your exact half zone before buying perennials.
A zone describes winter cold only. Summer heat, humidity, rainfall and soil decide whether a cold-hardy plant thrives, and planting dates for vegetables follow frost dates, not zones: two Oregon towns in the same zone can have last frosts weeks apart.
What Plants Grow Well Across Oregon?
134 plants in PlantoScan's catalogue are hardy in every zone from 6b to 9a, the zones that cover 77% of Oregon ZIP codes. Popular examples include hydrangea, chrysanthemum and poppy.
Hydrangea
Hydrangea macrophylla
Zone 5 – 9
AI generated
Chrysanthemum
Chrysanthemum morifolium
Zone 5a – 9b
PlantoscanAI generated
Poppy
Papaver somniferum
Zone 3a – 9b
AI generated
Carnation
Dianthus caryophyllus
Zone 5a – 9b
AI generated
Azalea
Azalea indica
Zone 6a – 9b
AI generated
Arugula
Eruca sativa
Zone 5a – 10b
AI generated
Alfalfa
Medicago sativa
Zone 3a – 10a
AI generated
Japanese Maple
Acer palmatum
Zone 5a – 9b
AI generated
Wisteria
Wisteria sinensis
Zone 5a – 9b
AI generated
Hardiness ranges come from PlantoScan's plant database; gardeners in Oregon's colder or warmer edge zones should check each plant's full range.
When Is the Last Frost in Oregon?
Across most Oregon ZIP codes, the average last spring frost falls between March 12 and June 4, from February 11 in Beaverton to June 11 in Burns. Tender vegetables such as tomatoes go out 1 to 2 weeks after the local date.
The last and first frost dates for Oregon cities include the safer 90% planting date, the fall frost date, growing season length and a tomato planting table for each city.
Frequently Asked Questions
- What planting zone is Oregon?
- Oregon spans USDA hardiness zones 5b to 9b on the 2023 USDA Plant Hardiness Zone Map. Zone 8b is the most common, covering 40% of the state's 473 ZIP codes, and zones 6b to 9a together cover 77%.
- What hardiness zone is Portland, Oregon?
- Portland is in USDA hardiness zone 8b (ZIP 97212), where the average coldest winter night reaches 15 °F to 20 °F. Its average last spring frost is February 25 and its first fall frost December 1.
- What hardiness zone is Salem, Oregon?
- Salem is in USDA hardiness zone 8b (ZIP 97301), where the average coldest winter night reaches 15 °F to 20 °F. Its average last spring frost is April 3 and its first fall frost November 1.
- What hardiness zone is Eugene, Oregon?
- Eugene is in USDA hardiness zone 8b (ZIP 97401), where the average coldest winter night reaches 15 °F to 20 °F. Its average last spring frost is April 11 and its first fall frost October 23.
- What is the coldest hardiness zone in Oregon?
- Zone 5b (−15 °F to −10 °F) is the coldest zone in Oregon, found in 1 ZIP code. The warmest is zone 9b (25 °F to 30 °F), around Newport and Brookings.
Zones: 2023 USDA Plant Hardiness Zone Map ZIP code table, USDA Agricultural Research Service and the PRISM Climate Group, Oregon State University, used without changes. Frost dates: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals. City locations and populations: U.S. Census Bureau Gazetteer files and Vintage 2024 population estimates. PlantoScan is not affiliated with or endorsed by these agencies.