Rhododendrons of North America

Spectacular spring flowering evergreen shrubs

The Rhododendron Family: Ericaceae

The genus Rhododendron includes nearly 1,000 species and countless numbers of cultivars (cultivated varieties). While azaleas are now included in the genus Rhododendron, there are some general differences between azaleas and rhododendrons. The most notable difference is that most rhododendrons are evergreen while most azaleas are deciduous (leaves fall off in winter). While indigenous to many nations, Rhododendrons are most common in China, Japan, and the eastern and northwestern United States.

Large Purple Rhododendron
Standing 12 feet tall and spreading 20 feet laterally,
this huge purple Rhododendron is a
real ‘show stopper’ in springtime!

Rhododendrons in the Northeastern US

Few spring flowering shrubs in the northeast command the same attention and respect as Rhododendrons. These evergreens are well known for their large pom-pom shaped flowers that appear in rich purple, red, pink and white colors. The blooms are further highlighted by a background of large evergreen leaves.

When Rhododendrons are sited correctly – eastern or northern exposures away from harsh winter winds – they will perform magnificently. The huge purple Rhododendron in the photo below gives ample proof of how well they thrive in the right location. Gardeners who desire to grow healthy Rhododendrons should also pay close attention to finding a spot in the garden with good drainage and acidic soil.

Rhododendron Care

Rhododendron trimming should be done within 30 days of when blossoms fade, so the flower buds for next year’s flower show aren’t inadvertently removed. Some gardeners also like to “dead head” spent blossoms that have become seed heads, but care must be given not to damage new growth.

VIDEO: How to ‘Deadhead’ Rhododendrons

Send your Rhododendrons into winter with adequate moisture in their root zones to counter the drying affects of winter winds on evergreen foliage. In exposed areas of the landscape, plants can be protected with burlap ‘shields’ attached to stakes – like fencing. An alternative winter defense is applying an anti-desiccant to the foliage.