Rain gardens, stream banks, and low-lying areas are the perfect settings for this showy, semi-aquatic shrub adorned with flowers resembling Victorian pincushions. Beekeepers call this plant “honey balls” for its abundant nectar production, and they plant it for the fragrant, creamy-white flowers that attract masses of bees and other pollinators. Buttonbush typically grows 6-10’ tall with a spreading, irregular shape. Occasionally, it grows 12-15’ tall, taking the form of a small tree with a multi-stemmed trunk. It flowers prolifically June through August in full sun but will tolerate part shade with less-frequent blooming periods. Moist to wet soils and even standing water are the preferred growing conditions. Plants grown in drier conditions and full sun may need supplemental water. Sometimes called “button willow” because of its spherical flower heads and preference for wet conditions, buttonbush adapts to a range of soil types--including sand, loam, clay, or limestone--and also does well in compacted soils. Buttonbush spreads by suckers to form colonies and is often used to develop and restore wetlands, control erosion, and create wildlife habitats.
Cephalanthus is a combination of the Greek words for “head” and “flower,” probably referring to the unusual sight of the extremely long styles emerging from masses of tiny, tubular-shaped flowers. More recently, buttonbush has been nicknamed “the COVID plant” for its resemblance to the iconic image of the fuzzy coronavirus ball. Buttonbush is an ideal replacement for the popular butterfly bush, because it attracts just as many pollinators as the favored non-native. The parade of wildlife continues into fall and winter as the seed heads mature into balls of reddish-brown nutlets that are a healthy fast-food buffet for a variety of waterfowl and other birds.
If planting in smaller spaces, prune to control height or cut to the ground every 3 to 5 years in late winter or early spring to rejuvenate the plant. Pruning lower limbs shows off its multi-stemmed trunk and gives it a more formal look.
Native habitats include edges of ponds, streams, and rivers; swamps; low-lying areas; prairie swales; and dry, limestone bluffs. Its showy blooms and nuts are great for bogs or ponds, fragrant gardens, and water gardens. To convert soggy areas into a pollinator paradise, plant buttonbush along with other water-loving plants, such as silky, autumn, or dune willow shrub; great blue lobelia; swamp goldenrod; sweet Joe-pye; and switchgrass.
Plant Characteristics:
Grows 6-10’ tall and wide, occasionally reaching 12-15’.
Prefers part shade but tolerates full sun.
Does best in average to boggy soils and adapts to a wide range of soil types.
White or pale-pink flowers bloom mid to late summer in densely packed, 1-2” flower heads on flowering stalks, usually at the ends of branches. Protruding styles give the flowers a starburst appearance. Rounded masses of reddish nutlets persist until early winter.
Narrowly ovate leaves occur in pairs or in threes, 6-8” long, with pointed tips, smooth margins, and a glossy upper surface.
Trunks are often multi-stemmed and twisted with many branches that are crooked or leaning. The bark is dark gray and somewhat peeling.
Wildlife Value:
Buttonbush is a host plant for 25 species of Lepidoptera larvae, including the Promethea, beautiful wood nymph, and definite tussock moths. It also hosts two gorgeous sphinx moths—hydrangea and titan. Various bee pollinators include honey, bumble, cuckoo, long-horned, leafcutting, and green metallic. Hummingbird, butterflies, wasps, flies, and skippers also visit the flowers. Shore birds and over 25 species of waterfowl, including wood ducks, eat the seeds. Some birds use the shrubs as nesting sites, and beavers use the wood as a source of food or construction material. Deer may occasionally browse the foliage.
Medicinal, Edible, and Other Uses:
Native Americans used a decoction of the bark as a wash for sore eyes and to treat diarrhea, inflammation, headaches, and venereal disease. The bark was chewed to relieve toothaches.
Caution: The leaves may be toxic to livestock and domesticated animals.