Buttonbush (Cephalanthus occidentalis), native to widely diverse regions of the world, is found in Ohio primarily in wetland areas, around pond margins, or in soils that are permanently moist. It occurs in the eastern half of the United States, the Great Plains, the southwestern United States, Mexico, Cuba, and eastern Asia. It is easily recognized in summer by its globular, pure white flowers that have projecting styles. Its glossy foliage, which emerges late as compared to other woody plants (mid-spring), is a second ornamental feature. This sprawling shrub, when found in the open in Ohio, reaches about 7 feet tall and 15 feet wide. As a member of the Madder Family, it is related to Coffee, Sweet Woodruff, Gardenia, and Partridge Berry, among others.
Planting Requirements - Buttonbush performs best in wet soils of variable pH, in full sun. It becomes more compact in its growth habit when sited in moist soils (organic or clay) that become dry in summer, but adapts to them. It is found in zones 5 to 11.
Potential Problems - Buttonbush is usually devoid of any serious disease or pest problems, so long as it is not sited in excessively dry soils.
Identifying Features - Buttonbush
Leaves of Buttonbush are shiny and elliptical, with prominent veins.
They are opposite or occasionally whorled on the numerous stems, which branch to the ground on this sprawling shrub.
The white, spherical, perfect flowers of Buttonbush, with their needle-like projecting styles, are truly unique among the flowering shrubs.
These early summer flowers become knobby green fruits on long peduncles, and change into dark brown to black fruits that persist throughout the winter.
Twigs of Buttonbush are smooth with lenticels, olive to gray-brown in color, and relatively plain in winter, with virtually invisible buds.
The mature bark is much more interesting, composed of gray flakes on the sprawling, wide-spreading branches.