Among the many plant groups admired by P.S. du Pont, rhododendrons and deciduous azaleas held a special place. Today, these beloved plants continue to enrich our landscape and collections.
Rhododendrons are integrated throughout the eastern end of the garden, while native azaleas—once showcased in expansive plantings beside the Main Fountain Garden—now serve as a signature element of Peirce’s Woods. This distinguished collection emphasizes both the conservation and advancement of US native deciduous azalea species and their hybrids, as well as a diverse array of evergreen rhododendrons.
Our plant evaluation program explores a wide spectrum of evergreen rhododendrons, with the goal of enhancing the diversity of broadleaf evergreens across the garden. Particular focus is placed on deciduous azaleas derived from southern US native species—especially those bred for exceptional floral displays and resistance to powdery mildew. In parallel, our evergreen rhododendron efforts prioritize unique species and cultivars that thrive in the environmental conditions of the Delaware Valley.
This collection fulfills heritage, display, research, educational, and germplasm preservation functions.
Curators: Tony Aiello & Peter Zale
Collection Highlights
Spring rhododendrons bloom in Peirce's Park.
Rhododendron canescens
Throughout the last century, Longwood has made continual efforts to strategically build a beautiful and diverse collection of rhododendrons.
Rhododendron austrinum Florida Flame Azalea
Rhododendron calendulaceum