1228 Cercidiphyllum japonicumCommon Names: katsura tree, katsuratree Family: Cercidiphyllaceae (katsura tree Family)
Katsura tree is a deciduous tree with a pyramidal or rounded form, but can become very wide spreading when it finds itself growing in the open. Trees usually have a trunk that branches just above the base. Mature trees can get 70 ft (21 m) tall with a spread of 50 ft (15 m) or more. The leaves are mostly opposite and more or less round, and look a lot like those of the redbuds (genus Cercis), including the American native, eastern redbud (Cercis canadensis). (Phyllum is from the Greek for leaf, thus: Cercidiphyllum.) Emerging leaves are bronze or purple before turning bluish green in summer. The show really starts in the autumn, though, when they turn shades of red, pink, orange and yellow. But it doesn’t end there. The fallen leaves have a sweet cinnamon or burnt sugar fragrance that makes them a delight to walk on.
The katsura tree is dioecious, with male and female flowers borne on separate trees. The flowers, opening before the leaves in early spring, are tiny and insignificant (to us, that is; they are certainly significant to katsura trees!) Fruits are dehiscent pods less than an inch (2.5 cm) long, and the seeds are very thin and winged.
Cercidiphyllum japonicum var. magnificum (native to high elevations in Japan) is a smaller tree than the type variety, but has larger leaves. It is sometimes considered a separate species. C. japonicum var. sinensis (native to China) is taller and usually has a single trunk. The cultivar ‘Aureum’ has purple new leaves and bright yellow autumn leaves. ‘Heronsood Globe’ forms a symmetrical mound no more than 15 ft (4.5 m) tall and wide. There is a weeping form known variously as the cultivar ‘Pendula’, or the botanical form Pendulum. What is probably the original ‘Pendula’ still graces the grounds of a temple on Honshu Island and has been there for at least 300 years where it is adored as though a national treasure.
In the wild, Cercidiphyllum japonicum (Katsura tree) is an understory tree in mixed woodlands in temperate Japan and China.
Katsura trees does best on rich, neutral to acidic soils and develops the best fall color on soils that are on the acidic side. Light: Grow katsura tree in full sun or dappled shade. Moisture: Katsura likes a moist but well drained soil. It is not drought tolerant and should get supplemental water during prolonged hot and dry periods. Newly planted trees should be watered frequently until well established. Hardiness: USDA Zones 4 - 8. In zone 8 and possibly zone 9, katsura tree needs to be in partial shade in good, moist soil. Propagation: Seed should be sown as soon as ripe. Semi-ripe cuttings can be rooted in summer. Young greenwood stem tips can be started in spring. Some of the cultivars (especially ‘Pendula’) are grafted onto species seedlings.
With its smoothly rounded and symmetrical crown, katsura tree is a fine lawn specimen. It has beautiful autumn foliage and its naked structure in winter is eye catching as well. Katsura tree is best grown in an open position in the landscape. As a street or avenue tree, it has few peers. Katsura trees often develop several trunks, but are easily trained to a central leader as you would want for a street tree. It’s a great shade tree, and one that has been allowed to develop several trunks above the base can shade a lot of area. This is a handsome ornamental in a public park, and it doesn’t get too big for the home landscape either. Walk under it in autumn and enjoy the spicy smell of the crunchy fallen leaves.
The Cercidiphyllaceae is a monotypic family. That is, there is only this one species in the family.
Steve Christman 11/09/14