Rhododendron grande is native to eastern Nepal, Sikkih and Buthan, as well as central Arunachal Pradesh and southern Tibet. It grows from 8,000 to 9,000 feet in elevation, being cold hardy to 15 degrees F.
Humboldt Botanical Garden’s R. grande is currently flourishing at 102 feet elevation, located in an area near the Wildberries Riparian Area. HBG received this plant from the Rhododendron Species Botanical Garden (www.rhodygarden.org) in late 2014. It was grown from seed collected in the wild by Steve Hootman, executive director and curator at the Rhododendron Species Botanical Garden.
Sir J. D Hooker, who first collected it in the Sikkim Himalaya and introduced to cultivation, said in his journal, “It seems to be shy of flowering, this season at least (1848); for it was with difficulty I could procure sufficient specimens to complete my drawing.”
HBG’s R. grande is not at all shy about flowering. This February it flowered for the first time and we’re excited because this is a rather rare and somewhat tender species. New leaf buds that appear during or immediately after flowering are beautiful. They are erect and silky, at first enveloped in large scales, so closely imbricated (overlapping like roof tiles). They are so large that they resemble cones of some species of pine.
The Chinese name for R. grande is ju kui dujuan, which means girat rhododendron. Fully developed leaves are among the largest of the genus Rhododendron, averaging 6- 12-inches long and 3- to 5-inches broad. Undersides of each leaf are clad in slivery-white indumentum (hairy covering).
In early spring rose-colored flower buds open to bell-shaped flowers 2- to 2 1/2 inches in diameter. Wax-like flowers are a creamy white.
Written by June Walsh
March 2019