Rhododendron
Rhododendron maximum
ShrubAbout Rhododendron
Rhododendron is a large evergreen shrub known for its showy clusters of large, bell-shaped flowers and thick, leathery leaves. It thrives in the cool, acidic, mountainous forests of the Appalachian region and is widely used in shade gardens. The leaves curl and droop in cold weather, a natural defense mechanism.
Quick Facts
How to Identify Rhododendron
- Large, thick, leathery, dark green evergreen leaves
- Showy clusters of bell-shaped flowers in late spring
- Leaves curl downward in cold temperatures
- Multi-stemmed, spreading, rounded habit
- Smooth, gray-brown bark
Care Guide
- Never plant too deeply; set root ball slightly above grade
- Water consistently; rhododendrons are very sensitive to drought
- Deadhead spent flower clusters to promote next year's bloom
- Mulch with pine bark, needles, or oak leaves to maintain acidity
- Avoid cultivation near roots, which are very shallow
Known Issues (2)
Sudden Oak Death
MODERATEA water mold disease that has killed millions of oaks and tanoaks along the Pacific coast since the mid-1990s. It also infects over 100 other plant species that can serve as carriers, including rhododendron and bay laurel.
Affecting 2 regions
Phytophthora Root Rot
HIGHA group of water-mold diseases that attack the roots and root collar of many tree species. Phytophthora thrives in wet, poorly drained soils. It destroys fine roots and can girdle the trunk at the soil line. Affected trees show a general decline that is often misdiagnosed as drought stress. Oaks, dogwoods, rhododendrons, and many other species are susceptible.
Affecting 31 regions