Index / Search / Rhododendron albiflorum

§1 Plant

Rhododendron albiflorum Hook.

vernacular Cascade azalea — species · Ericaceae

USDA: RHAL2
GBIF: 2883078
Rank: species

Cascade azalea (Rhododendron albiflorum) — Platephotograph · no rights reservedCC0 · public domain source · iNaturalist ↗

§2Habit & range

Growth habit: Shrub
Duration: Perennial
Group: Dicot
Family: Ericaceae Juss.
Genus: Rhododendron

§2a

Native status, by region

CAN Canada Native
L48 Lower 48 States Native

§2b

County-level range

· 34 counties across 5 states/territories

Legend Native · 34 Introduced · 0 Both · 0 Hover a county for detail.

§3Cultivation specs · USDA

Recorded by the USDA Plant Materials Program.

§3a

Tolerances

Drought: None
Shade: Medium
Moisture use: High
Fire: Medium
Salinity: None
Anaerobic: None
CaCO₃: None
Hedging: High

§3b

Climate & soil

Cold tolerance: 7 °F minimum
Frost-free days: 200 min.
Precipitation: 59–100 in/yr
pH range: 4.5–6.5
Root depth: 12 in min.
Fertility need: Medium
Soil texture: coarse, medium

§3c

Form & growth

Growth form: Multiple Stem
Growth rate: Moderate
Lifespan: Moderate
Mature height: 6 ft
Height @ 20 y: 6 ft
Foliage texture: Coarse
Foliage colour: Green
Porosity (summer): Dense
Porosity (winter): Porous
Flower colour: White
Fruit colour: Black
Fire resistant: No
N fixation: None
Toxicity: Severe

§3d

Reproduction

Bloom period: Late Summer
Seed abundance: High
Seed begins: Summer
Seed ends: Fall
Spread rate: Rapid
Stratify: No
Seeds / lb: 2,000,000
Propagation: seed, cuttings, bare root, container

§3e

Use & availability

Commercial availability: Contracting Only
Nursery stock: Yes
Browse palatability: Low
Graze palatability: Low
Palatable, human: No
Protein potential: Low
Lumber: No
Christmas tree: No

§4Counties, by state

Recorded in 34 counties across 5 states/territories.

Colorado view state ↗ 3 N ▾

Idaho view state ↗ 3 N ▾

Montana view state ↗ 3 N ▾

Oregon view state ↗ 8 N ▾

Washington view state ↗ 17 N ▾

§5Sources & provenance

USDA PLANTS

Symbol, taxonomy, distribution, cultivation specs, native status. Public domain.

plants.usda.gov/RHAL2 ↗

GBIF Backbone

Canonical taxonomic identity, synonym resolution, cross-refs. CC0.

gbif.org/species/2883078 ↗

Record version

Cached and built locally. Source version on this record:

usda-plants-mt-2026-05-26

fetched 2026-05-26T20:46:58Z