Each fall, we sing the praises of fall allium and autumn crocus blooms. This year, however, a special mention must be made for the glorious gladiolus! Especially the delicate, 4-inch salmon pink flowers of the salmon gladiolus (Gladiolus oppositiflorus spp. salmoneus).
Hailing from the summer rainfall areas of the cold, higher elevations of the Drakensberg Mountains of South Africa, this beautiful wild species has proven amazingly hardy in the Chicago Botanic Garden’s Graham Bulb Garden over the last five years—including a couple of winters with record-setting cold temperatures!
Two characteristics of its native habitat nominated the gladiolus for trial at the Garden: first, it is a winter-growing bulb in South Africa, which translates to summer growth in North America. Second, this plant thrives in moist soils in grassy areas—it was perfect for the site we chose in the Bulb Garden.
Based upon its initial success in our plant trial program, other gladiolus (also currently in full flower) were added to the trials. We’ve also discovered that these wild species thrive and multiply in well-drained soils (but do not tolerate flooded soils). The beautiful, red-flowered Gladiolus saundersii is also native to the Drakensbergs, but from a higher, colder, and snowier habitat. And a third selection is probably a close relative of Gladiolus dalenii var. primulinus. Discovered in an old, abandoned farmstead in North Carolina, and sold under the name ‘Carolina Primrose’, this gladiolus generally blooms in July and early August (although it is still blooming now). All have come through the record-breaking cold of the last couple of winters.
Gladiolus is the largest genus in the Iridaceae (iris plant family) with 255 species worldwide; 166 of them in southern Africa. The genus was given its name by Pliny the Elder, in reference to the size and shape of the leaves, which are similar in shape and size to a short sword favored by Roman-era gladiators: the gladius.
It’s not easy to find commercial sources for these bulbs, but it’s well worth the effort to obtain an elegant, refined, fall-flowering, and hardy gladiolus.
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