wetland shrub
Great rhododendron
Rhododendron maximum
Also known as Great Laurel, Wild Rhododendron, Rosebay Rhododendron, White Laurel, Rosebay
1 of 2Native to the Northeast and the Southeast
Western Maine to New York and Ohio, southern, especially in the mountains, south to northern Georgia
- Light Partial shade Sun tolerance
- Moisture Moist to wet Moisture preference
- Zones 4–8 Cold to heat range
- Bloom Jun–Aug Flowering time
- Height up to 30 ft to 9.1 m
- Life cycle Perennial Annual to perennial
In the garden
A wetland shrub for partial shade and consistently moist to wet soil. At up to 30 ft, it needs room in rain gardens, pond edges, and damp low spots. Hardy in USDA zones 4–8.
Growing conditions
Light
Full sun Partial shade Full shade
Moisture
Dry Moist Wet
Hardiness zones
Find your zone:
Pollinators & wildlife
- Bees Common Eastern Bumble Bee
also Western Honey Bee, Eastern Carpenter Bee, Two-spotted Bumble Bee +4 more
Perplexing Bumble Bee, Yellow-banded Bumble Bee, Azalea Mining Bee, Early Bumble Bee - Butterflies Eastern Tiger Swallowtail also Silver-spotted Skipper, Canadian Tiger Swallowtail, Hobomok Skipper
- Moths Hummingbird Clearwing also Yellow-spotted Webworm Moth
- Also visited by
- Beetles: Gaurotes cyanipennis
Butterflies that use this plant
Documented host and nectar records. Each links to a planting guide for that butterfly.
Full plant details
Where it grows
- Habitat
- WetlandThe wild plant community it grows in.
- Native range
- The Northeast and the SoutheastUnited States (19): CT, DC, GA, KY, MA, MD, ME, NC, NH, NJ, NY, OH, PA, RI, SC, TN, VA, VT, WV. Where it grows wild on its own, by state and province.
- Native distribution
- Western Maine to New York and Ohio, southern, especially in the mountains, south to northern GeorgiaThe same native range, usually more exact than the state list, and often noting where it has spread beyond it.
Growing conditions
- Light
- Partial shadeHow much sun it takes, from full sun to full shade.
- Moisture
- Moist to wetThe soil dampness it prefers, from dry to wet.
- Hardiness zones
- USDA 4–8 · Canadian 5–7The cold-to-heat climate range it survives.
- Soil
- Cool, moist, well-drained soilThe soils it grows in naturally.
- Soil texture
- Light to medium (sandy to loamy)The soil grade it prefers, from sand to clay.
- Soil pH
- 4.0–5.5The acidity to alkalinity it tolerates (7 is neutral).
- Soil quality
- LowHow rich a soil it needs. Many natives prefer lean soil and flop in rich beds.
- Water use
- MediumHow 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 30 ft (to 9.1 m)Typical mature height.
- Life cycle
- PerennialWhether it lives a single season (annual), two (biennial), or returns for years (perennial).
- Growth rate
- SlowA relative ranking versus other plants of the same type (USDA), not an absolute rate.
- Shape
- Semi-ErectIts overall silhouette.
- Root depth
- 18+ in (46+ cm)How far the roots reach, a guide to drought resilience and transplanting.
Flowers, foliage & fruit
- Type
- ShrubWhat kind of plant it is.
- Bloom
- Jun–AugWhen it flowers.
- Flower color
- White, PinkThe bloom color, or colors.
- 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
- ~5 million seeds per poundNotes on the seed and how to sow it.
- Seed spread rate
- SlowHow readily it self-sows. Slow or none means well-behaved, not a spreader.
- Seedling vigor
- LowHow strongly young seedlings establish.
- Vegetative spread
- NoneWhether it creeps outward or stays put in a clump.