Japanese Katsura
(Cercidiphyllum japonicum)
The Japanese Katsura, sometimes called the Judas Tree, is a medium-sized shade tree growing to 40-60’ tall in cultivation and just as wide when provided with adequate space but may attain heights exceeding 100-150’ in the wild. A native of Japan and China, it was introduced to the Arnold Arboretum in Massachusetts in 1878. It is one of only two species in the genus Cercidiphyllum, the other is magnificum, a smaller variety that grows at altitude and seldom grows to 30’, and which is found only on Japan’s middle island of Honshu in the wild.
Katsura can be found with a single stem but often branches low and develops into a multi-stemmed tree. Pyramidal in habit when young and taking on a rounded habit with age, with a full, thick crown that casts a dense shade.
The flowers are small and not particularly showy in nature, with the male flower emerging in late winter before bud break and the female flowers blooming as the leaves expand. Leaves emerge with a bronze to red or purple color, turning a bluish green by summer. Cercidiphyllum takes its name from its heart shaped leaves, closely resembling redbud (Cercis). The leaves are smaller than redbud and are arranged opposite to sub-opposite on the stem instead of alternately like redbud. The leaves are also unique in that they are attached to the petiole at a 90-degree angle, similar in appearance to lily pads.
Fall color can be an attractive pale yellow to apricot. When the leaves fall it may sometimes have a fragrance of burnt sugar or cotton candy. By late summer and early fall the twigs may be lined with ½”-3/4” green winged seeds that will turn brown and persist into winter, aiding in tree identification during dormancy.
The bark is ash gray with shaggy plates that twist around the trunk in the pattern of a barber’s pole. Katsura performs best in full sun with moist, well drained, organically rich soils. Alkaline soils will often cause thin and off-color foliage. Trees will also prematurely turn fall color, drop their leaves or develop leaf scorch in arid soils, on windy sites or during periods of drought.
Having no serious disease or insect pests, Katsura is an attractive mid-sized shade tree with multiple seasons of interest. When given enough space to grow and adequate moisture, Katsura can be a low maintenance addition to most landscapes.
