A graceful tree of many charms, Stewartia pseudocamellia (Korean or Japanese stewartia) is known in Japan as the summer camellia, natsu-tsubaki. It is related to both Camellia and Franklinia, fellow members of the Theaceae (tea family). In the 1980s, Holden horticulturist Peter Bristol collected seed in Korea from trees about 50 and 40 feet tall on rocky, well-drained slopes at elevations of 1,250 and 2,625 feet. Two notable associated species were Cornus kousa (kousa dogwood) and Styrax obassia (fragrant snowbell).
The Holden Arboretum has several mature specimens, the oldest and two of the largest being at Lantern Court next to the north terrace and in the vale west of the main drive. Fine specimens may also be found west of Blueberry Pond, on the southeast side of Spruce Knoll and at the David G. Leach Research Station. Growth rate has been 6-10”/yr. with our tallest reaching 40 feet. About 30 percent of the trees planted have survived to date. Mortality has been high on heavy soils that get waterlogged or are prone to drought, but very low on moist acidic well-drained sandy loam. A sheltered site is preferred.
The gorgeous white camellia-like blossoms begin appearing on our trees in mid- to late June adorning them until mid- to late July. The flowers are 2-3” across and retain their ring of yellow stamens after they fall, making a lovely carpet beneath the branches. The 1” long seed pods are green at first then turning brown and releasing their ¼” flattened seeds in October and November. The downward facing capsules remain on the tree for a year after they open. Occasional seedlings sprout in our gardens under and near a parent tree but have very little potential for invasiveness. This species exhibits a relatively narrow range of ecological amplitude.
The handsome 3-5” medium to dark green leaves are rarely affected by insects or disease and not only provide a suitable background for the flowers but are very attractive in their own right.
In October, the foliage typically turns shades of orange-red with interior leaves yellow and purplish highlights on branch tips but some individuals turn purplish or purplish-burgundy. The show usually lasts around three weeks. In late April the leaves break bud and their undersides are covered with silky white hairs that shimmer in the sunshine.
Its mesmerizing bark is fairly smooth and thin with plates peeling off in very thin patches. The sleek trunk and limbs of Stewartia pseudocamellia are colored shades of brown, warm grey, buff, light green and cream.