woodland shrub
Pacific rhododendron
Rhododendron macrophyllum
Also known as California Rhododendron, California Rosebay, Red Rhododendron
1 of 2Native to California, Oregon, and Washington and southern Canada
Coastal British Columbia and Washington, through the Cascades to northern California; isolated stations on Vancouver Island
- Light Part shade to shade Sun tolerance
- Moisture Dry to moist Moisture preference
- Zones 5–10 Cold to heat range
- Bloom May–Jul Flowering time
- Height up to 15 ft to 4.6 m
- Life cycle Perennial Annual to perennial
In the garden
A woodland shrub for part to full shade and dry to moist soil. Its pink and purple flowers peak in June. At up to 15 ft, it needs room in shade gardens and woodland edges. Hardy in USDA zones 5–10.
Growing conditions
Light
Full sun Partial shade Full shade
Moisture
Dry Moist Wet
Hardiness zones
Find your zone:
When it blooms
The Pacific rhododendron's pink and purple flowers bloom May to July, peaking in June. This early-summer display draws bees and butterflies.
Pacific rhododendron blooms pink & purpleFoliage
Pollinators & wildlife
- Bees Yellow-faced Bumble Bee
also Black-tailed Bumble Bee, Fuzzy-Horned Bumble Bee, Yellow-fronted Bumble Bee +4 more
Yellowish Cuckoo Bumble bee, Sitka Bumble Bee, Azalea Mining Bee, Fog-belt Bumble Bee - Butterflies Red Admiral also Clodius Parnassian, Occidryas editha
- Beetles Scripted Long-horned Beetle also Evodinus monticola vancouveri
- Also visited by
- Flower flies: Black-margined Flower Fly, Western Calligrapher
Butterflies that use this plant
Documented host and nectar records. Each links to a planting guide for that butterfly.
- Red admiralnectar
Full plant details
Where it grows
- Habitat
- WoodlandThe wild plant community it grows in.
- Native range
- California, Oregon, and Washington and southern CanadaUnited States (3): CA, OR, WA. Canada (1): BC. Where it grows wild on its own, by state and province.
- Native distribution
- Coastal British Columbia and Washington, through the Cascades to northern California; isolated stations on Vancouver IslandThe same native range, usually more exact than the state list, and often noting where it has spread beyond it.
Growing conditions
- Light
- Part shade to shadeHow much sun it takes, from full sun to full shade.
- Moisture
- Dry to moistThe soil dampness it prefers, from dry to wet.
- Hardiness zones
- USDA 5–10 · Canadian 3–9The cold-to-heat climate range it survives.
- Soil
- Moist to drier, well-drained soilThe soils it grows in naturally.
- Soil pH
- 5.5–7.0The acidity to alkalinity it tolerates (7 is neutral).
- Soil quality
- MediumHow rich a soil it needs. Many natives prefer lean soil and flop in rich beds.
- Water use
- HighHow thirsty it is, a rough guide to how often to water.
- Salinity tolerance
- NoneHow well it copes with salty soil, near roads or the coast.
- Lime (CaCO₃) tolerance
- NoneHow well it copes with chalky, lime-rich soil.
Growth & form
- Height
- up to 15 ft (to 4.6 m)Typical mature height.
- Life cycle
- PerennialWhether it lives a single season (annual), two (biennial), or returns for years (perennial).
- Growth rate
- ModerateA relative ranking versus other plants of the same type (USDA), not an absolute rate.
- Shape
- ErectIts overall silhouette.
- Root depth
- 12+ in (30+ cm)How far the roots reach, a guide to drought resilience and transplanting.
Flowers, foliage & fruit
- Type
- ShrubWhat kind of plant it is.
- Bloom
- May–JulWhen it flowers.
- Flower color
- Pink, PurpleThe bloom color, or colors.
- Fruit/Seeds
- ripens Jun–SepThe seed or fruit it sets after flowering.
- Toxicity
- Poisonous if eatenWhether any part is poisonous to people or pets.
Propagation & seed
- Cold stratification
- Not requiredWhether seed needs a cold, moist spell before it will germinate.
- Propagation
- Bare root, container, cuttings, seedHow to start new plants.
- Seed
- ~3 million seeds per poundNotes on the seed and how to sow it.
- Seed spread rate
- RapidHow readily it self-sows. Slow or none means well-behaved, not a spreader.
- Seedling vigor
- MediumHow strongly young seedlings establish.
- Vegetative spread
- NoneWhether it creeps outward or stays put in a clump.