Rhododendron macrophyllum

Common Names

Pacific Rhododendron, California Rhododendron, Coast Rhododendron, California Rosebay, Big Leaf Rhododendron, Western Rhododendron

Summary

Pacific rhododendron is an evergreen broadleaf shrub native to the Pacific Northwest, ranging from British Columbia to northern California, typically 6–12 ft tall with an upright, dense habit and large leathery dark-green leaves 7–20 cm long. It produces terminal clusters of bell-shaped flowers in pink to pale pink–rose-purple (rarely white), usually in spring to midsummer, with 10–20 blooms per cluster, and the bloom is not fragrant, while flowers attract pollinators such as bees and butterflies.

Cultivation favors partial shade to shade and moist, acidic, well-drained soils; mulch to conserve moisture; provide wind protection and frost protection in exposed sites. Prune after flowering to shape or remove dead wood. It is hardy to USDA Zone 7 and can be propagated by seed, semi-ripe cuttings in late summer, or layering; in landscapes, it serves as an ornamental shrub for woodland gardens, habitat hedgerows, and erosion control, while supporting native pollinators.

Lifecycle

Perennial

Height

3-25 feet

Spread

8-16 feet

Hardiness Zones

Zones 6-9

Sunlight Requirements

Ideally partial shade to partial sun.

Soil Type

Acidic, well-drained, humus-rich soil

Soil Drainage

Moist but well-drained soil

Soil pH

Acidic soils; pH 4.5–6.0 (often 4.5–5.5).

Bloom Color

Pink to Purple

Bloom Time

Spring

Foliage Color

Dark green

Fall Foliage Color

Green; no fall color change

Leaf Lifecycle

Evergreen broadleaf

Growth Rate

Moderate

Seasons of Interest

Spring, Summer, Fall, Winter

Propagation Methods

Seeds, Cuttings, Layering

Attracts Wildlife

Attracts bees, hummingbirds, butterflies, other pollinators, and birds