Common Buttonbush

Buttonbush (Cephalanthus occidentalis) in early August in the shallows of Lake Hall, Alfred B. Maclay Gardens State Park, Tallahassee, FL.
R. F. Polomski, ©2019, Clemson Extension

Buttonbush (Cephalanthus occidentalis) is often lauded for its utility rather than its beauty. Its commercial introduction in 1735 was primarily for beekeepers (hence, its other common name of honey-bells), who cultivated this deciduous shrub as a pollen and nectar resource for honeybees. This wetland shrub can be found in low-lying areas, swamps, marshes, bogs, and wetlands, and along the edges of ponds, streams, and rivers. It is often used to develop and restore wetlands, control erosion in riparian areas, and create wildlife habitats. In addition to these functional attributes, buttonbush offers ornamental value. Its unique-looking pin cushion-like balls of white, fragrant flowers that appear in mid- to late summer draw the attention of pollinators and people alike.

Hardiness

Buttonbush (USDA Cold Hardiness Zones 5 to 11) boasts a broad natural range that extends as far north as New Brunswick, Nova Scotia, and Ontario, south to Florida, and west to Nebraska and Texas. There are scattered populations in Arizona, New Mexico, southern California, and northern Mexico.

Buttonbush leaves and flowers (Cephalanthus occidentalis) in mid-August in the
SC Botanical Garden, ©2019, Clemson, SC.

The spherical cluster of flowers of buttonbush (Cephalanthus occidentalis) resembles a pincushion due to the long styles that extend from each one of the creamy-white tubular flowers.
R. F. Polomski @2019, Clemson University

Dense clusters of reddish-brown nutlets of buttonbush (Cephalanthus occidentalis) in early November in the Santa Barbara Botanic Garden.
R. F. Polomski @2019, Clemson University

Mature Height/Spread/Form

Buttonbush typically grows up to 6 to 8 feet tall and wide, but can attain a height of 12 to 15 feet with an equal spread. While its open, irregular form has been described as disheveled or unkempt, buttonbush can look more attractive by pruning lanky, wayward branches to outward growing side shoots. It can also be limbed-up and maintained as a small, multi-trunked tree.

Growth Rate

Buttonbush is a fast-growing, short-lived shrub. It spreads to form thickets by suckering, which results in individual plants arising from its roots.

Ornamental Features and Ecological Values

Buttonbush is one of the last native American shrubs to leaf-out in the spring when its oval to elliptical glossy green leaves emerge and unfold. These leaves provide food for the larval stage of, most notably, the showy hydrangea sphinx and titan sphinx moths. They are also a food source for many pollinating insects and hummingbirds.

Buttonbush tends to go unnoticed until it starts flowering in June through August. Each gumball- to golf ball-sized floral sphere (1- to 1½-inch diameter) is comprised of many scented, creamy-white tubular flowers packed closely together. The long styles that extend above the four anthers make it look like an artificial satellite or pincushion. (The style is a long slender stalk that joins the stigma at its tip, which receives pollen produced by anthers, with the ovary at the bottom which produces the seed.) Each flower lasts up to 4 days. These spherical blooms are attached like ornaments to the ends of branches and occasionally along the length of shoots by 1- to 2½-inch long stalks called peduncles.

After the flowers are fertilized by pollinators, a hard-ball of reddish-brown nutlets develops and matures from August to November. These nutlets (or “buttons”) persist into winter and provide seasonal interest. They are also consumed by a variety of waterfowl.

The fall color of buttonbush leaves ranges from insignificant to mottled brown and yellow.

Landscape Use

Buttonbush requires full sun to partial shade in moist to wet soils. This shrub thrives in low-lying areas that may not dry out until late in the season, such as bioswales or bogs, or pond and stream banks. Supplemental watering will be necessary for full sun locations that may dry out because buttonbush cannot tolerate drought.

When buttonbush gets too large or looks too unruly, rejuvenate the shrub by cutting it close to its base or crown in early spring before new growth emerges. See HGIC 1053, Pruning Shrubs, for more information.

Problems

Buttonbush has no serious insect pest or disease problems. Planting it in the proper site with moist conditions will help to prevent leaf loss and branch dieback.

Cultivars

‘Bailoptics’ PP 29,475 [Fiber Optics®] Fiber Optics® has a compact growth habit and grows 5 to 6 feet high and wide. New shoot growth is reddish-brown, which is unlike the typical green of the species. This cultivar was discovered as a seedling in Hastings, MN.

‘Bieberich’ [Sputnik™]: This cultivar grows 10 to 15 feet high and 10 to 12 feet wide with a rounded form and pale pink flowers. The glossy leaves turn coppery-bronze in the fall. ‘Bieberich’ was discovered by Steve Bieberich of Sunshine Nursery in a native stand in Oklahoma.

Flowers of ‘Bieberich’ [Sputnik™] in early July in the SC Botanical Garden, Clemson, SC.
R. F. Polomski @2019, Clemson University

Closeup of ‘Bieberich’ [Sputnik™] leaves in the SC Botanical Garden, Clemson, SC.
R. F. Polomski @2019, Clemson University

‘Keystone’: This cultivar has a vigorous growth habit with dense shoots and leaves. It grows 8 to 12 feet high and 5 to 8 feet wide. It was chosen primarily from open-pollinated, northeastern populations. Introduced in 1996 by the USDA Natural Resources Conservation Service and the Pennsylvania Game Commission, ‘Keystone’ is a proven performer from Maryland to Maine.

‘Kolmoon’ [Magical® Moonlight]: This compact buttonbush grows 5 to 8 feet tall and 4 to 6 feet wide at maturity.

‘Select A Dark Green’ (also sold as ‘J.N. Select A’) [Ping Pong™] Ping Pong™ is a rounded form that matures to a height and spread of 8 feet. It was selected from open-pollinated seedlings at Johnson’s Nursery in Wisconsin.

‘Kolmoon’ [Magical® Moonlight] is a compact cultivar suitable as a deciduous screen in small garden spaces.
Courtesy of Plants Nouveau, LLC.

The glossy, dark green leaves of ‘Select A Dark Green’ [Ping Pong™].
Courtesy of UpShoot™ Horticulture Marketing Firm

The round clusters of creamy-white flowers serve as backdrop for dark green leaves of ‘Select A Dark Green’ [Ping Pong™].
Courtesy of UpShoot™ Horticulture Marketing Firm

‘SMCOSS’ USPP 26,543 [Sugar Shack^®]: This very compact, dwarf cultivar grows 3 to 4 feet high and wide with an upright, mounded, dense and bushy growth habit. The glossy green leaves are tinged with red in the spring and fall. ‘SMCOSS’ was the result of a controlled breeding program in Grand Haven, MI.

Shrub border of ‘SMCOSS’ [Sugar Shack®] buttonbush in bloom.
Photo Courtesy of Proven Winners – www.provenwinners.com.

Globular clusters of mature reddish-brown nutlets of ‘SMCOSS’ [Sugar Shack®] buttonbush, which is typical of the species.
Photo Courtesy of Proven Winners – www.provenwinners.com.

References:

1. Connor, K. 2004. Cephalanthus occidentalis buttonbush, p. 170-172. In: J. K. Francis (ed.). “Wildland shrubs of the United States and its territories: thamnic descriptions”: vol. 1. Gen. Tech. Rep. IITF-GTR-26. San Juan, PR: U.S. Department of Agriculture, Forest Service, International Institute of Tropical Forestry, and Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 30 July 2019 <https://www.fs.fed.us/rm/pubs_series/iitf/iitf_gtr026.pdf>.
2. Dirr, M. A. 2009. Manual of Woody Landscape Plants. 6th ed. Stipes Pub., Champaign, IL.
3. “’Keystone’ buttonbush (Cephalanthus occidentalis); A Conservation Plant Released by the USDA NRCS Big Flats Plant Materials Center, Corning, New York.” USDA-Natural Resources Conservation Service, Big Flats Plant Materials Center, Corning, New York, 14830. Published [March 2015]. 9 Dec 2019
4. Foote, L. E. and S. B. Jones, Jr. 1994. Native Shrubs and Woody Vines of the Southeast: Landscaping Uses and Identification. Timber Press, Portland, OR.
5. Spira, T. P. 2011. Wildflowers and Plant Communities of the Southern Appalachian Mountains and Piedmont: A Naturalist’s Guide to the Carolinas, Virginia, Tennessee, and Georgia. UNC Press, Chapel Hill.
6. Wennerberg, S. 2004. “Plant Guide: Common buttonbush Cephalanthus occidentalis ” USDA-NRCS. 9 Dec 2019. <https://plants.usda.gov/plantguide/pdf/pg_ceoc2.pdf>

Originally published 01/20