Horticulture Highlight: Pearlbush, Exochorda sp.

Think of pearl, some could own a favorite pearl(s), others may have read Tracy Chevalier’s novel Girl with a Pearl Earring and/or per chance seen the film or play of the same name. Maybe, a few think of Janis Joplin’s (1943-1970) final album, Pearl (1971), which sold four-million U.S. copies to achieve quadruple platinum and included her biggest hit “Me and Bobby McGee”. But honestly how many of you have seen a Pearlbush, Exochorda sp. in peak blossom lighting up a landscape? If not, come visit us soon and see for yourself.

Exochorda is a genus of flowering shrubs/small trees within the ROSACEAE, rose family, that are all native to China and central Asia. Our biggest and most beautiful plant is Wilson Pearlbush, Exochorda giraldii var. wilsonii. which in full flower visually dominates its immediate location at the intersection of Palm Avenue and Myrtle Path. Michael Dirr, renowned horticulturist, author and woody plant expert is quoted from the sixth edition of his book, Manual of Woody Landscape Plants, that five decades of plant students, enthusiasts and experts alike have been referencing, “The finest specimen I have observed is located at Mount Auburn Cemetery…it is about 18’ high and 22 to 25’ wide.”

The white, 5-petaled, odorless flowers are 1-2” across and before opening, each expanding bud appears as a small pearl, hence the common name. The variety name pays tribute to Ernest Henry Wilson (1876-1930), an iconic figure a century ago, with international fame in the worlds of botany and horticulture. Between 1899 and 1922 his plant explorations and collections introduced over 2000 taxa of plants to Europe and the United States from China, Japan, Korea, Australia, New Zealand, Malaysia and South Africa. He authored eleven related books, innumerable journals and magazine articles. Yet today, he has often become another man passed into history.

On Pyrola Path near Orange Path, you will find a smaller hybrid Pearlbush, Exochorda xmacrantha ‘The Bride’ with similar white flowers but growing just 6’ high and 15’ wide. We have several other smaller Pearlbush throughout our living collection. Pearlbush, Exochorda sp. unfortunately remains an under used ornamental shrub with great spring stature.

Mount Auburn’s living collection includes notable abundant diversity. Our recent 2024 Plant Collections Analysis documents a total of 20,392 plants or massed plantings which represent 2561 different plant taxa, within 492 genera from within 128 botanical families. On a future visit to Mount Auburn spend some time mimicking E. H. Wilson doing your own plant exploration, but please no collecting.