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Pacific Rhododendron*

Rhododendron macrophylum (accepted: Rhododendron macrophyllum) · Ericaceae · all Rhododendron records

Your local evidence lens

Separate evidence questions, never one approval badge

Set a ZIP to compare this record with state distribution, native range, USDA hardiness, and invasive records.

A genus split is not a placement verdict. Set a ZIP to read the local documented split.

1. Fire evidence and conditions

Fire evidence: Fire-resistant — location does not change the cited classification.
Fire-performance conditions: 1 condition stated in cited fire-evidence rows.
Fire ecology context: No section-reviewed fire-ecology context is normalized.
Placement evidence: 3 source placement records; source schemes remain separate.
Evidence regions: British Columbia; Oregon; Oregon (Willamette Valley); Pacific Northwest (Oregon / Washington / Idaho)
Maintenance: No sourced horticultural maintenance assertion is normalized; fire-test conditions do not supply maintenance advice.

Typed publication scope: 1 scope across 1 cited fire source

Fire-resistant Landscape Plants for the Willamette Valley (EM 9103) · Official scoped edition
- Willamette Valley (OR footprint); partial normalized coverage · 2015-02-01
  OSU Extension says EM 9103 highlights fire-resistant plants that thrive under Willamette Valley growing conditions. FireApproved publishes 172 exact owners only as valley context. The guide shares the PNW 590 lineage and is not a second independent vote or statewide site clearance.

2. Why this plant is relevant here

State distribution: Documented in CA, ID, OR, WA.
Native range: No current cited or legacy state native range is normalized.
Introduced / established: No introduced or established row is normalized; that does not prove native status.
USDA hardiness: 3 applicable cited hardiness statements overlap but have different boundaries; compare each complete source row.

3. Legal, ecological, and broader status

Legal-list status: Set a location for an exact legal-list result; source silence is not clearance.
Seed-list status: Set a location to compare the separate state noxious-weed seed layer.
Reported invasive here: No ecological invasive report is normalized; that does not prove noninvasiveness.
Broader regional context: Aggregate AK, HI, and L48 evidence is shown only as regional context, never as an exact-state finding.
Federal context: Federal designations remain separate from state legal-list results.

How to read this page

The status above is computed from the cited rows below: independent recommendations can support a fire-resistant result, an avoid row can produce keep-away, and disagreement stays visible as conflict. Placement notes preserve each source’s own scheme rather than translating unlike rules into one scale. This is evidence about a plant, not permission to plant it in every part of the defensible space; Zone 0 remains noncombustible.

Pacific Rhododendron* (Rhododendron macrophylum) — Photo: (c) David Anderson, some rights reserved (CC BY) (CC BY), via iNaturalist. Species-typical, not necessarily this cultivar.

Form: shrub
USDA hardiness: Applicable source statements overlap but have different boundaries; compare each source
Mature height: ~15 ft
Water need: high
Grows in: CA, ID, OR, WA
Rated in: British Columbia; Oregon; Oregon (Willamette Valley); Pacific Northwest (Oregon / Washington / Idaho)
Family: Ericaceae
Evidence: 4 cited sources

Plant hardiness evidence

These values describe the plant source. Your ZIP zone comes from the separate 2023 USDA Plant Hardiness Zone Map. Whole-zone values stay whole-zone, and a single unresolved value is not treated as a tolerance range. Different source boundaries stay separate: overlapping statements are compared independently, while only ranges with no shared zone are called a conflict.

Fire-resistant Landscape Plants for the Willamette Valley (EM 9103) · EM 9103, February 2015 · as of 2026-08-26

6–9 explicit range · whole zone precision · source stated

Source taxon: Rhododendron macrophyllum · exact match.

Source location: Pacific Rhododendron profile (PDF page 143).
Fire-Resistant Plants for Home Landscapes (PNW 590) · record broadleaf-evergreens:Pacific rhododendron · 2023-10 · as of 2026-08-26

6–9 explicit range · whole zone precision · source stated

Source taxon: Rhododendron macrophyllum · accepted name match.

Source location: Pacific rhododendron profile, USDA hardiness zones field.
USDA PLANTS Database — Plant Characteristics · record RHMA3 · PLANTS Help Document 2022; characteristics cache retrieved 2026-08-23 · as of 2026-08-26

Minimum 7b · no upper limit documented · half zone precision · derived containing band

Exact source measurement: 7°F; mapped only to its containing half-zone.

Source taxon: Rhododendron macrophylum · source identifier match.

Source location: PlantCharacteristics record 65367, Temperature, Minimum (°F).

Conditions in the fire evidence

These describe tested or rated plant material. They are not horticultural maintenance instructions.

green: Fire-Resistant Plants for Oregon Home Landscapes evidence row

Where its sources say to plant it

Placement rules below use each source's own distances or named zones, tied to its rating. They are not interchangeable with the directory's current Zone 0 guidance.

Fire-Resistant Plants for Oregon Home Landscapes: Southern and Western Oregon [osu-frn6-oregon-regions] (with its recommendation)
Fire-resistant Landscape Plants for the Willamette Valley: Pacific Rhododendron profile (PDF page 143) [osu-em-9103-profile] (with its recommendation)
Fire-resistant plant profile galleries: Pacific rhododendron — Rhododendron macrophyllum [osu-2023-broadleaf-evergreens-gallery] (with its recommendation)

The evidence

Grouped by what each source concluded. Primary evidence rated the plant itself (a lab, field program, or original curation); corroboration compiled or republished another source's rating and resolves to its root lineage.

Last verified 2026-08-23. JSON (CC BY 4.0)

Profiles: USDA PLANTS · GBIF · iNaturalist · Wikidata · ITIS

Rhododendron macrophylum (Pacific Rhododendron*). FireApproved. https://fireapproved.com/plants/rhododendron-macrophylum/. Last verified 2026-08-23.