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Plant Database

Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

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Rhododendron maximum (Great laurel)
Cressler, Alan

Rhododendron maximum

Rhododendron maximum L.

Great Laurel, Wild Rhododendron, Rosebay Rhododendron, White Laurel, Rosebay

Ericaceae (Heath Family)

Synonym(s): Rhododendron ashleyi

USDA Symbol: rhma4

USDA Native Status: L48 (N), CAN (N)

Evergreen, thicket-forming shrub or tree with short, crooked trunk, broad, rounded crown of many stout, crooked branches, and large white blossoms. Great-laurel or rosebay rhododendron is a loose, open, broadleaf evergreen with multiple-trunks, upright branching, and the largest leaves of all native rhododendrons. The plant grows 4-15 ft. in the north, but can grow 30 ft. high in favorable sites. Its foliage is dark blue-green and leathery. Large, bell-shaped, white to purplish-pink, spotted flowers appear in terminal clusters of 16-24.

Rosebay Rhododendron is abundant in the Great Smoky Mountains National Park. Often grown as an ornamental, it is one of the hardiest and largest evergreen rhododendrons. The wood is occasionally used for tool handles, and a home remedy has been prepared from the leaves.

 

From the Image Gallery

32 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Shrub
Leaf Retention: Evergreen
Leaf Arrangement: Alternate
Leaf Complexity: Simple
Breeding System: Flowers Bisexual
Fruit Type: Capsule
Size Notes: Up to about 30 feet tall, often much shorter.
Leaf: Dark Green
Fruit: Brown

Bloom Information

Bloom Color: White , Pink
Bloom Time: Jun , Jul , Aug

Distribution

USA: AL , CT , DC , GA , KY , MA , MD , ME , NC , NH , NJ , NY , OH , PA , RI , SC , TN , VA , VT , WV
Canada: NS
Native Distribution: W. ME to NY & OH, s., especially in the mts., s. to n. GA
Native Habitat: Moist, dense woods; steep stream banks; mountain slopes

Growing Conditions

Water Use: Medium
Light Requirement: Part Shade
Soil Moisture: Moist , Wet
Soil pH: Acidic (pH<6.8)
CaCO3 Tolerance: None
Soil Description: Cool, moist, well-drained soil.

Benefit

Warning: Rhododendrons contain poisonous substances and should not be ingested by humans or animals. Honey made from flowers also may be toxic. POISONOUS PARTS: All parts. Highly Toxic, May be Fatal if eaten. Symptoms include salivation, watering of eyes and nose, abdominal pain, loss of energy, depression, nausea and vomiting, diarrhea, weakness, difficult breathing, progressive paralysis of arms and legs, coma. Toxic Principle: Andromedotoxin. (Poisonous Plants of N.C.)
Conspicuous Flowers: yes
Attracts: Birds

Value to Beneficial Insects

Special Value to Bumble Bees

This information was provided by the Pollinator Program at The Xerces Society for Invertebrate Conservation.

Propagation

Description: Combine seeds loosely with sphagnum moss and sprinkle lightly over a 2:1 perlite/peat mixture. Germinate under mist or a plastic tent. Optimum temperatures for germination are 45-50 degrees. Transplant seedlings to acid soil with a high content of orga
Seed Treatment: No pretreatment is necessary.
Commercially Avail: yes

Find Seed or Plants

View propagation protocol from Native Plants Network.

Mr. Smarty Plants says

Shrub for barrier fence in Alexandria, Virginia
August 19, 2009
Hi. we need plants to act as a barrier fence, 15 feet tall, partial shade. We are considering a holly or virginia magnolia. What can you suggest? thank you, Nikita
view the full question and answer

National Wetland Indicator Status

Region:AGCPAKAWCBEMPGPHIMWNCNEWMVE
Status: FAC FAC FAC FAC
This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

From the National Organizations Directory

According to the species list provided by Affiliate Organizations, this plant is on display at the following locations:

Mt. Cuba Center - Hockessin, DE

Bibliography

Bibref 1620 - Gardening with Native Plants of the South (Reprint Edition) (2009) Wasowski, S. with A. Wasowski

Search More Titles in Bibliography

Web Reference

Webref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.

From the Archive

Wildflower Newsletter 1988 VOL. 5, NO.2 - Researching Wildflower Seed Quality, Wildflower Center Receives $500 -000 Gift, ...
Wildflower Newsletter 1992 VOL. 9, NO.1 - Research Update, Creating Native Lawn with Sod, Director's Report, What Makes Pl...

Additional resources

USDA: Find Rhododendron maximum in USDA Plants
FNA: Find Rhododendron maximum in the Flora of North America (if available)
Google: Search Google for Rhododendron maximum

Metadata

Record Modified: 2022-10-11
Research By: TWC Staff

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