American hornbeam, Carpinus caroliniana, is an often overlooked tree that would greatly enhance anyone’s home garden. Its relatively small stature (20-30 feet tall) means it can fit into most small landscapes with no problem. It is hardy to Zones 3 to 9.
American hornbeam is the only North American native of the genus Carpinus. The other common name of this tree is ironwood or musclewood. The very attractive bark is smooth and fluted, resembling flexing muscles. Its hard wood was used by early Americans to make bowls, tool handles, and ox yokes.
Hornbeams are best placed into a natural setting but they do well in shade or sun, can tolerate wet sites, and even withstand some flooding. It prefers deep, fertile, moist, and slightly acidic soils although it will grow in drier sites. Compacted soils are not the best for this tree, especially in areas that have undergone grade changes.
The tree blooms usually from April to June. Flowers are either male or female catkins. Male flowers are somewhat attractive but female flowers are not showy. A winged nutlet forms after the female flower fades.
The canopy of the hornbeam can be pretty dense, especially in full sun. The leaves are alternately arranged on the stem, 2 to 5 inches long. New leaves in the spring emerge as a reddish-purple color, then turn dark green in the summer.
Fall color can be quite variable including colors of yellow, orange, red, and reddish-purple.
Successful transplanting has been shown to be difficult. When planting, be sure to use ball and burlapped or container plants.
Although the straight species is a great choice, there are several cultivars available: Ball O’ Fire™, Firespire™, and Palisade™.
Submitted by Beth Wilson, Agent for Horticulture, Pulaski Co. Cooperative Extension Service