Underutilized Landscape Plant: Carpinus Caroliniana - American Hornbeam

Musclewood refers to hornbeam's fluted, smooth trunk, blue beech to the bluish-grey color of the bark. The fluted trunk is one of the characteristics that allow us to enjoy American hornbeam even in the winter. The leaves are elliptical, simple, and alternate with double serrated margins seldom marred by insect or disease. American hornbeam produces a nutlet carried by a three-lobed leafy bract. While you can purchase single-stem specimens, American hornbeam also grows in clumps of two or more stems. American hornbeam steals the show in autumn when it develops a beautiful orange and scarlet fall color.

American hornbeam bark and nutlet. Photo: Mike Masiuk, Penn State

The orange and scarlet of the American hornbeam in autumn is a showstopper. Photo: Mike Masiuk, Penn State

This understory native extends from the Northwoods of Minnesota, where I first experienced it, follows the Mississippi River south, extending east to the coast. As an understory tree, it prefers partial shade, but tolerates full sun and full shade, tolerating less sun in warmer climes. Its easy-going nature allows it to do well in a wide range of pH and moisture levels, although it would rather not be subjected to prolonged drought. Despite its small mature size, in northern climates, it is not a good candidate as a street tree as it has low salt tolerance. This tree needs to be planted in the spring, it experiences poor establishment when planted in the summer or fall. Due to its deep, spreading lateral roots it can be difficult to transplant. It also has a low tolerance for exposed sites.

American hornbeam (Carpinus caroliniana) mature tree at 30-inch DBH. Photo: T. Davis Sydnor, The Ohio State University, Bugwood.org

Good landscape companions for American hornbeam include Ostrya virginiana (eastern hophornbeam), Hamamelis virginiana (witch-hazel), Amelanchier spp. (serviceberry), Cercis canadensis (redbud) and Cornus florida (flowering dogwood). Smaller companions to integrate American hornbeam into the landscape are Viburnum dentatum (arrowwood), Ilex verticillata (winterberry), and Itea virginica (Virginia sweetspire).  Several cultivars of blue beech exist, although they are not easily found in the trade. Firespire ™ is a narrow upright cultivar with beautiful red-orange fall color and a mature size of 20 ft. high and 10 ft. wide. Palisade ® is a 20 to 30 ft. high by 15 ft. wide cultivar with yellow-orange fall color. I believe you will find much to love about Carpinus caroliniana and hope you make a point to use it to its full potential.

References

• The Morton Arboretum, Mortonarb.org
• Plants.CES.NCSU.edu