Chinese Fringetree (Chionanthus retusus): The Tree That Flowers Like Rice

Plant Highlights · Chinese Fringetree · East Asia

For about two weeks in late spring, a small tree from Korea, Japan and China disappears under a fall of white so heavy that farmers once read the harvest in the bloom.

9 min read · By Fiona von Grey · Aiken, South Carolina

I.Snow flower

The genus name is a description, and an exact one. Chionanthus comes from the Greek chion, snow, and anthos, flower, and anyone who has stood under a Chinese fringetree in late May will tell you the botanists were not exaggerating. The flowers are pure white and faintly sweet, each one split into four narrow, strap-like lobes about half an inch to an inch long, and they come in loose panicles at the ends of the new shoots. On a tree in full flower the panicles are so numerous that the leaves all but vanish, and the whole crown reads as a single drift of white froth.

Chionanthus retusus is a small deciduous tree of eastern Asia, native to central and southern China, Taiwan, South Korea and Japan. In cultivation expect something between 10 and 30 feet tall and roughly as wide, a rounded, spreading head on a short trunk, though wild trees in their home range can reach well beyond that. The species epithet is a small joke for the leaf-minded: retusus means retuse, a rounded leaf tip with a shallow notch in the middle, as if someone had pressed a thumbnail into the end of each leaf.

The tree belongs to Oleaceae, the olive family, which puts the fringetree in company with lilacs, ashes, jasmines and the tea olives. That last kinship will make sense to anyone who has met both: the same clean, leathery, opposite leaves, the same habit of flowering in clouds. We wrote about the tea olives' own place in East Asian culture in Osmanthus and the Moon Palace, and the fringetree belongs to the same story.

II.The rice tree and the what-is-that tree

Few trees have been looked at so fondly, by so many people, for so long. In Korea the fringetree is ipap-namu, 이팝나무, and the most common explanation of the name runs back to ipap, an old word for a bowl of white rice: the massed flower heads look exactly like rice heaped high and steaming. A second theory ties the name to ipha, the solar term that marks the beginning of summer, which is roughly when the trees bloom. The two explanations are not rivals so much as neighbors, and both tie the tree to the farming year.

The connection went further than the name. In the south of the peninsula, a heavy flowering was taken as a sign of a good rice harvest to come. There is sense under the folklore: fringetrees bloom best where spring water is plentiful, and so are the paddies. Several old trees are protected as national natural monuments, mostly in the southwest of the country. One in Gimhae, Cheongok-ri, is put at around 500 years old and stands some 60 feet tall. Today the species is an increasingly popular street tree in Korean cities, common enough in places like Daegu that the bloom has become a civic event.

Japan gave the tree a name with a wink in the middle. The proper name is hitotsubatago, but the nickname is nanja monja, roughly "what on earth is that," a label once handed out to any striking old tree whose identity people could no longer place. The best known Japanese stand grows wild near Inuyama in Aichi Prefecture, first recorded in 1822, rediscovered in 1922, and designated a national natural monument on 7 March 1923. Only a handful of trees remain there. Japan has a long habit of honoring individual trees as monuments, and we touched on that same reverence from the conifer side in The Cedar That Is Not a Cedar.

III.Reading the tree through the year

The bloom is the headline, but the tree keeps quieter company through the other fifty weeks, and those weeks are most of what you live with.

Spring. The leaves come first, and the flowers follow in late spring at the ends of the current season's shoots. In Aiken that usually means May. Expect a lighter show some years: the species has a tendency toward heavy bloom in alternate years, which is not a sign that anything is wrong.

Summer. The foliage is the summer story: opposite, leathery, glossy dark green and pale beneath. Leaves on young plants are often finely toothed, and the toothing tends to disappear as the tree matures, which confuses people who bought a sapling with serrated leaves and later find smooth ones.

Fall. Fruiting trees carry clusters of dark blue, olive-like drupes about half an inch long, ripening from late summer into autumn and taken by birds as soon as they color. Fall color is a clear yellow in a good year and an indifferent one in a poor year. Do not plant the tree for autumn alone.

Winter. Older trees develop grey-brown bark that ridges and peels in strips, so the bare frame has something to show. The architecture is low and broad and handsome against a dark evergreen.

IV.Two fringetrees, two calendars

The Southeast has a fringetree of its own, and the question we hear most is which one to plant. The honest answer is both, if you have the room, because they are not doing the same job.

That last row deserves a sentence of its own. The emerald ash borer, which has gutted ash populations across eastern North America, has been documented attacking the native white fringetree, a relative of ash in the same family. In laboratory and field work the Chinese species proved resistant, with no field infestations found and no larvae surviving rearing trials. Nobody should take that as a reason to stop planting the native, which matters to our insects in ways an import cannot. The finding is a reason to plant the two side by side rather than putting every egg in one basket.

V.Siting and planting this fall

October is the right month for a fringetree here. The soil is still warm, the tree has stopped pushing new growth, and the roots have the whole cool half of the year to settle in before the first serious heat. We laid out the general argument in Plant It in the Cooling, and small flowering trees are among the plants that gain most from it.

One honest caution comes with the tree: the fringetree is slow out of the gate. Expect a modest first year and a tree that starts to look like something in year three or four. After that, the tree will flower every spring for longer than most of us will be gardening.