Pacific Rhododendron

Rhododendron macrophyllum

Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Ericaceae
Genus:
Rhododendron
Species:
Rhododendron macrophyllum

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Shrub , Tree
Height:
12-20 ft
Light Requirements:
Part Shade, Shade
Drought Tolerance:
High
Bloom Months:
apr, may, jun, jul
Bloom Colors:
Pink, Purple
Evergreen Shrub:
Yes
Landscaping Shrub:
Yes

Native Range

United States: California, Oregon, Washington, Canada: British Columbia

Keystone Species Ranking

Caterpillar Keystone:
★★☆☆☆ Based on number of butterfly and moth species using this genus as host plant (Source: National Wildlife Federation)

Host Plant for Caterpillars

Hemigraphiphora plebeia

Reported Fauna Sightings

Bees: Black-tailed bumble bee (Bombus melanopygus), Black-tailed bumble bee (Bombus melanopygus), Common eastern bumble bee (Bombus impatiens), Common eastern bumble bee (Bombus impatiens), Confusing bumble bee (Bombus perplexus), Confusing bumble bee (Bombus perplexus), Fernald cuckoo bumble bee (Bombus flavidus), Fernald cuckoo bumble bee (Bombus flavidus), Fuzzy-horned bumble bee (Bombus mixtus), Fuzzy-horned bumble bee (Bombus mixtus), Obscure bumble bee (Bombus caliginosus), Obscure bumble bee (Bombus caliginosus), Sitka bumble bee (Bombus sitkensis), Sitka bumble bee (Bombus sitkensis), Yellow head bumble bee (Bombus flavifrons), Yellow head bumble bee (Bombus flavifrons), Yellow-faced bumble bee (Bombus vosnesenskii), Yellow-faced bumble bee (Bombus vosnesenskii)

Soil Requirements

Soil Type:
rich, well-drained loamy soil
pH:
4.5 - 6.0 (acidic to slightly acidic)
Drainage:
excellent drainage required
Moisture:
consistently moist
Notes:
prefers organic matter-rich environments

Germination Information

Pre-treatment: Seeds are soaked in a 1% hydrogen peroxide solution for 24 hours, rinsed, and then placed in water for an additional 24 hours. Following this, seeds are subjected to a 30-day cold, moist stratification at 1 to 3 °C. They can be placed in fine mesh bags in a covered container or sown into trays filled with stabilized medium plugs and sealed in plastic bags. Containers or trays are then placed in refrigeration at 1 to 3 °C. Stratified seeds in mesh bags should be rinsed or plugs moistened weekly. If mold is evident, seeds should be treated with 1% hydrogen peroxide.

Source: npn.rngr.net