The Katsura (Cercidiphyllum japonicum) is a deciduous tree species native to Japan and China. Katsura trees once grew wild in North America and Europe, according to Gerald Klingaman at the University of Arkansas Cooperative Extension Service, but they disappeared during the Pleistocene Era. Botanists reintroduced the species to the United States during the 19th century. As of 2011, growers cultivate them as park, street or landscape trees.
Cultivated Katsura trees grow between 40 and 60 feet tall with a 20- to 30-foot spread, but wild trees can grow taller than 100 feet. They have rough brown bark and a conical or spreading crown depending on the tree, with dense, heavy foliage. The bluish-green, heart-shaped leaves of a Katsura tree resemble those of redbud trees (Cercis spp.) according to the University of Connecticut. The foliage changes to apricot or yellow in the fall and releases a spicy-sweet fragrance. Small reddish blossoms emerge in the spring, followed by 0.75-inch green seed pods.
Katsura trees are available in several different cultivars. Pendula, which has pendulous or weeping branches, grows approximately 20 feet tall with a 10-foot spread. Several other pendulous varieties include Amazing Grace and Tidal Wave. Heronswood Globe is a dwarf variety that grows around 15 feet tall and has a dense, rounded crown. Ruby, another dwarf variety, has purplish-blue leaves and grows around 30 feet tall. The leaves of the Aureum cultivar are greenish-purple when they first bud, but they change to yellow as they age.
Katsura trees are hardy in United States Department of Agriculture hardiness zones 4 through 8. They grow best in partial sunlight and well-drained, nutrient-rich, moist soil. Katsura trees cannot tolerate drought conditions and will shed their leaves if the tree becomes too dry. They thrive best in sites that offer protection from strong, hot sunlight and harsh winds, and benefit from a layer of mulch below the canopy to help maintain soil moisture. They have moderate to rapid growth rates and propagate by seeds or cuttings.
Katsura trees are relatively free of serious insect and disease problems, according to the Missouri Botanical Garden. However, they do not transplant easily and require regular watering during droughts. The foliage tends to scorch if exposed to harsh winds, drought conditions or high summer temperatures. The limbs break easily, according to Edward F. Gilman and Dennis G. Watson from the University of Florida IFAS Extension, and they need regular pruning to maintain their form and structure.