Pacific Rhododendron (Macrophyllum)

The Pacific Rhododendron (Macrophyllum) is generally described as a perennial tree or shrub. This is native to the U.S. (United States) has its most active growth period in the spring and summer . The Pacific Rhododendron (Macrophyllum) has dark green foliage and inconspicuous purple flowers, with an abuncance of conspicuous black fruits or seeds. The greatest bloom is usually observed in the spring, with fruit and seed production starting in the summer and continuing until fall. Leaves are retained year to year. The Pacific Rhododendron (Macrophyllum) has a moderate life span relative to most other plant species and a moderate growth rate. At maturity, the typical Pacific Rhododendron (Macrophyllum) will reach up to 15 feet high, with a maximum height at 20 years of 10 feet.

The Pacific Rhododendron (Macrophyllum) is easily found in nurseries, garden stores and other plant dealers and distributors. It can be propagated by bare root, container, cuttings, seed. It has a rapid ability to spread through seed production and the seedlings have medium vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below 7°F. has none tolerance to drought and restricted water conditions.

Plant Basics
Growth Rate Moderate
General Type Tree, Shrub
Growth Period Spring, Summer
Growth Duration Perennial
Lifespan Moderate
Plant Nativity Native to U.S.
Commercial Availability Routinely Available
Physical Characteristics
Bloom Period Spring
Displays Fall Colors No
Shape/Growth Form Multiple Stem
Drought Tolerance None
Shade Tolerance Intermediate
Height When Mature 15
Vegetative Spread None
Flower Color Purple
Flower Conspicuousness Yes
Fruit/Seed Abundance High
Fruit/Seed Seasonality Summer Fall
Seed Spread Rate Rapid
Gardening Characteristics
Propagations (Ways to Grow) Bare Root, Container, Cuttings, Seed
Moisture Requirements High
Cold Stratification Required No
Minimum Temperature 7
Soil Depth for Roots 12
Toxic to Nearby Plants No
Toxic to Livestock No
After-Harvest Resprout Ability No
Responds to Coppicing No
Growth Requirements
pH Range 5.5–7 pH
Precipitation Range 55–55 inches/yr
Planting Density 600–1200 indiv./acre
Soil Textures Fine, Medium
Soil Depth for Roots 12
Minimum Frost-Free Days 270 day(s)
Salinity Tolerance None
CaCO3 Tolerance None
Sustainability & Use
Leaf Retention Yes
Palatability Low
Fire Resistant No
Causes Livestock Bloating None

Source: USDA, NRCS, PLANTS Database,
National Plant Data Center, Baton Rouge, LA 70874-4490 USA