Donald R. Egolf, Ph.D.

 

Years: 

1928–90

Year Hutchinson Medal awarded:

1982

Donald R. Egolf was a distinguished U.S. horticulturist and
plant breeder whose influential career spanned several decades.

Donald Roy Egolf was known throughout the horticultural world for the excellence of his cultivars and for his high standards. His contribution to the nursery industry and the American public had far-reaching implications

Career & Contributions:

  • U.S. National Arboretum (1958–90)
    Egolf served as a horticulturist and plant breeder at the U.S. National Arboretum in Washington, D.C.
  • Woody Ornamental Breeding
    He introduced and tested a wide range of ornamental trees and shrubs, including at least five viburnum cultivars that won Gold Medal Awards from the Pennsylvania Horticultural Society. Egolf contributed to more than 650 new varieties overall.

Major Plant Contributions:

Crape Myrtles (Lagerstroemia)

  • In the 1960s, Egolf pioneered breeding dwarf crape myrtles for compact size and powdery mildew resistance by crossing Lagerstroemia fauriei with existing hybrids.
  • He established large-scale screening—planting around 200,000 seedlings—and discarded any with mildew susceptibility.
  • Ultimately, he released 29 cultivars, each named after Native American tribes (e.g., ‘Catawba,’ ‘Arapaho’).

Althea (Rose-of-Sharon, Hibiscus syriacus)

  • Developed sterile, compact cultivars in the 1960s, such as the ‘Aphrodite’ variety, which was designated a Louisiana Super Plant. These sterile forms offered easier maintenance and prevented unwanted reseeding.

Viburnums

  • Bred several noteworthy viburnums, including Viburnum × burkwoodii 'Conoy' (released 1988), recognized for exceptional hardiness and earning the 1997 Gold Medal Award.

Redbuds

  • The Chinese redbud Cercis chinensis 'Don Egolf' (also called ‘Don Egolf Miniature Redbud’) was named in his honor. It is a sterile, compact ornamental tree with hot-pink spring flowers and fall foliage.

Publications & Legacy:

Egolf wrote several horticultural works, including:

  • Lilac Plant Source List (1977)
  • The Lagerstroemia Handbook/Checklist: A Guide to Crape Myrtle Cultivars (1978)
  • A Checklist of Pyracantha Cultivars (1995)

These publications contributed significantly to plant industry knowledge and naming conventions.