western red cedar (Thuja plicata), photographi

Can I Grow Western Red Cedar in Oregon?

USDA Zones 5a-10a · Plant zone range 4-10

Yes — Strong Match

western red cedar (zones 4-10) covers every zone Oregon contains (5a-10a), so hardiness is not what limits it anywhere in the state.

Western Red Cedar in Oregon — the short answer

Western Red Cedar in Oregon: hardy in zones 4–10, shade, against a state median of ~213 frost-free days.

Plant zones
4-10
Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
Oregon zones
5a-10a
USDA PHZM 2023
Frost window
Feb 25 - Apr 26 – Oct 19 - Nov 26
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
86 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

Score your parcel · free

Your yard isn't the whole zone.

Oregon spans zones 5a-10a, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score western red cedar against your parcel's actual hardiness, soil, and sun.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

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Oregon is not one climate

Oregon’s winter-low ladder runs across 36 counties, from zone 6 in Klamath County to zone 9.5 in Curry County. That is 35°F between the two counties’ average coldest night — the difference between western red cedar overwintering in the ground and coming under cover.

6 zonesKlamath County9.5 zonesCurry County

The middle half of 36 counties runs 6.58.5 zones, with a median of 7.5 zones — a 3.5-zone span end to end.

Measured across 36 Oregon counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Where in Oregon Fits Best

Even within Oregon's zones 5a-10a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for western red cedar (USDA PHZM 2023):

Zone Comparison

Western Red Cedar Needs

  • USDA Zones: 4-10
  • Sun: Shade
  • Mature size: 60 ft tall
  • Drought tolerance: Low

Oregon Has

  • USDA Zones: 5a-10a
  • Last Hard Freeze (28°F): Feb 25 - Apr 26
  • First Hard Freeze (28°F): Oct 19 - Nov 26
  • Annual Rainfall: 8-90 inches
  • Common Soils: Volcanic, Silt loam (Willamette), Sandy loam

Plant Zone Range (zones 4-10)

4a
10b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.17.1

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Western Red Cedar in Oregon

The frost window

Across Oregon, the last spring hard freeze (28°F) clears between Feb 25 and Apr 26, and the first fall hard freeze lands between Oct 19 and Nov 26 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 176-day window you can count on — up to 274 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.

Winter standing

Oregon runs as cold as USDA zone 5, and no sourced winter-hardiness floor is on record for western red cedar, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether western red cedar is a permanent planting or a replant-every-spring crop for you turns on your own zone within Oregon; check its hardiness range against that before treating it as long-lived ground.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Growing Season Fit

The zone check says western red cedar survives winter here. Whether the season is long enough — and warm enough — is a different question.

Chill hours

Western Red Cedar requires ~800 chill hours (32-45°F dormancy window). Oregon typically banks ~2500 chill hours per winter (from PRISM 1991-2020 climate normals), which keeps this plant on track.

GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.

Soil + Drainage Fit

Western Red Cedar likes near-neutral soil (pH 5.1-7.1). That's the common-ground band across Oregon's volcanic and silt loam (willamette) — a soil test confirms it for your site.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Oregon soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

What Else to Consider for Western Red Cedar in Oregon

Zone compatibility tells you about winter cold survival — but Oregon growers also need to think about:

West side: excessive rain and overcast skies reduce sun for warm-season crops

East side: arid conditions (8-15 inches rainfall) require irrigation

Slug pressure is extreme in western Oregon

Mountain areas have very short seasons (60-90 frost-free days)

What to actually do about these — and the constraints that apply to every Oregon grower, not just western red cedar — is covered on the Oregon growing guide.

Where in Oregon Western Red Cedar Is Zone-Hardy

Western Red Cedar is rated for USDA zones 410. Every one of Oregon’s 36 counties sits inside that band — from Klamath County at zone 6a to Curry County at zone 9b — so winter cold is not what decides this plant anywhere in the state. What is left to vary is your own parcel: slope, shelter and cold-air drainage routinely move a site half a zone either way from the county figure.

Across those 36 counties Oregon’s winter-low ladder runs from zone 6a in Klamath County to zone 9b in Curry County 3.5 USDA zones of spread, which is 35°F between the two counties’ average coldest night of the year. That is why a statewide hardiness answer is where you start and not where you finish.

The planting window moves with it. Klamath County holds its last hard freeze (28°F) until about Jun 9, while Lincoln County is clear by Feb 3 126 days apart. Set western red cedar out on your county’s date, not the state’s.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F killing freeze — earlier than the folk 32°F "last frost". Western Red Cedar’s zone 410 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.

Oregon Cooperative Extension

For Oregon-specific cultivar recommendations, planting calendars, and pest pressure for western red cedar, the canonical source is OSU Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Western Red Cedar native to Oregon?

Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Western Red Cedar as native to Oregon. Planting it supports the pollinators and wildlife that evolved alongside it.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

Common Questions About Growing Western Red Cedar in Oregon

When can I plant Western Red Cedar in Oregon?

Oregon's last spring hard freeze (28°F) clears between Feb 25 and Apr 26, and the first fall hard freeze lands between Oct 19 and Nov 26 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Western Red Cedar, so this page does not state whether it overwinters in Oregon and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.

What hardiness zone is Western Red Cedar grown in across Oregon?

Oregon spans USDA hardiness zones 5a-10a (USDA ARS PHZM 2023). Western Red Cedar carries a range of zones 4-10, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical Oregon site have?

A typical Oregon site sees ~213 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Western Red Cedar should be matched against that window, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Western Red Cedar native to Oregon?

Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Western Red Cedar as native to Oregon. Planting it supports the pollinators and wildlife that evolved alongside it.

How should I amend the soil for Western Red Cedar in Oregon?

Western Red Cedar prefers pH 5.1-7.1 (USDA PLANTS). That sits in the common-ground band across Oregon soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will Western Red Cedar actually grow on my specific land in Oregon?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores western red cedar against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in Oregon

State-level data is a sketch. Your Growable Ground report scores western red cedar against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Oregon western red cedar averages can't show:

Your soil pHYour frost-free days — Oregon averages 213Your sun & shade

We read public map data around Oregon — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Oregon western red cedar average

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