Horticulture Highlight: Astilbe, Astilbe sp.

Horticulture Highlight: Astilbe, Astilbe sp.
…It is a morning in July, hot and clear.
Out in the field, a bird repeats its quaternary call,
four notes insisting, I’m here, I’m here…
-Elizabeth Spires
During July, various planting beds have Astilbe declaring with their plume-like flowers, “I’m here, I’m here.” Astilbe as with Forsythia, Fothergilla, Iris, Rhododendron, Stewartia, and Ginkgo is a plant genus having the same common and Latin name. The name’s etymology derives from the Greek “a” (without) and “stilbe” (brilliance or shine). The tiny 1/16-inch flowers may be without brilliance, but with multiple stems each bearing scores of these flowers within any erect or arching panicle, the overall appearance is beautiful and dramatic.
Classified within the botanical family SAXIFRAGACEAE, the genus, Astilbe includes 18 species, primarily native to Asia but with two species native to North America. Feathery foliage is common to all species and cultivated varieties. Usually the leaves are 2-3 times ternately compound (divided into three parts), with the leaflets having a doubly serrate margin.
Asian species were popular introductions to Europe (then the U. S.) from the late 1700’s onward. Notable early plant explorers associated with introducing Astilbes include Sweden’s Carl Peter Thunberg (1743-1828) and Bavarian physician-botanist Philipp Franz von Siebold (1796-1866). However today the dominant name attached to Astilbes belongs to George Arends (1862-1952), a nurseryman from Ronsdorf, Germany. Working with Astilbe seeds, described by some as about the size of a speck of dust, he introduced the hybrid Astilbe xarendsii. W. George Schmid in his An Encyclopedia of Shade Perennials comments, “…By far the largest of several groups of hybrids in commerce is Astilbe xarendsii… now includes not only Arends’ complex crosses… but those contributed by hybridizers in France, the Netherlands, and other countries. The nomenclature of these hybrids is confused…”
Regardless of confused nomenclature, these modern hybrids bloom in white, pink and red, either in full sun or deep shade with showy plumes of differing lengths and fullness. After the flowers have faded to a brown color, the dried panicles may remain upright adding diminished but still vertical accents. On your next visit to Mount Auburn look for some of our Astilbe at Asa Gray garden, Spruce Knoll, Rosebay Avenue and Bigelow Avenue among other locations.
Heavy July. Too rampant and too lush;
High Summer, dull, fulfilled, and satiate,
Nothing to fear, and little to await.
The very birds are hush…
-Vita Sackville West
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