Culture
Easily grown in average, medium to wet, well-drained soils in full sun to part shade. Tolerant of a wide range of soil conditions including both wet and dry soils. Tolerant of seasonal flooding. Prefers moist fertile loams.
Noteworthy Characteristics
Catalpa ovata, commonly called Chinese catalpa, yellow catalpa and Japanese catalpa, is a small deciduous tree that typically grows to 30’ tall and as wide with a spreading crown. It is native to forested areas in western China. Broad-ovate, light green leaves (to 10” long and wide) are usually entire but sometimes 3-5 lobed. Leaves abruptly taper to points at the tips and are mostly cordate at the bases. Leaves are glabrous except for downy leaf veins beneath. Foliage turns an undistinguished yellow in fall. Flowers are attractive, but not as showy as C. bignoniodes (southern catalpa) and C. speciosa (northern catalpa). Bell-shaped, orchid-like, yellowish-white flowers (each to 3/4” long) with purple and orange inner spotting appear in panicles (to 10” long) in late spring (late May to early June in St. Louis). Flowers give way to long, slender, green seedpods (to 16” long and 1/3” wide). The seedpods mature in fall to dark brown and then split open lengthwise to release the seeds within. Bark of mature trees is fissured, prominently ridged and pale gray-brown. Chinese catalpa has escaped gardens and naturalized in some states in the eastern U.S.
Genus name comes from a North American Indian name.
Specific epithet means ovate or egg-shaped.
Problems
No serious insect or disease problems. Susceptible to verticillium wilt, leaf spots, mildew and twig blight. The larvae (caterpillars) of the catalpa sphinx moth may do considerable damage when feeding on the leaves.
Uses
A mature, symmetrically rounded catalpa tree can be a tree of great beauty, particularly in spring when the foliage is young and the flowers are in bloom. Unfortunately, it is otherwise a rather coarse tree that many believe does not deserve a prominent place in the landscape. Branches are brittle and mature trees infrequently exhibit classic form. Foliage also tends to depreciate as the growing season progresses, the large leaves being subject to damage from hail, wind, insects and sometime disease. It can be effectively used in the landscape for difficult areas such as moist low spots or dry areas with poor soils.