Buttonbush

Cephalanthus occidentalis

Description & Overview

Buttonbush brings more than its sweet scent and charming blooms into your garden – it is a magnet for wildlife! Another common name for this shrub is honey bells as its spherical white flowers are a favorite among honeybees and bumblebees. It is adapted to shorelines and swamps with saturated soil. It can tolerate water depths of up to three feet and does extraordinarily well in streambanks, riverbeds, and floodplains.


Core Characteristics

Mature Height: 6-8′
Mature Spread: 6-8′
Growth Rate: Moderate
Growth Form: Arching, Irregular, upright
Light Requirements: Full Sun to Partial Shade
Site Requirements: Thrives in wet sites, intolerant of dry sites. Indifferent to soil texture.
Flower: Small, fragrant, white globular
Bloom Period: Early to mid-July
Foliage: Oval to elliptical, glossy green
Fall Color: Yellowish to dark bronze
Fruit Notes: Russet brown spherical cluster of achenes

Suggested Uses:

Buttonbush is a distinctive shrub with blossoms that resemble pincushion composed of dense clusters of tiny white tubular flowers. Buttonbush is Indigenous to swamps, wetlands, flood plains, and other riparian areas that are inundated for at least part of the year. It is useful for erosion control or stream bank stabilization as well. Because this plant is easily grown in moist or wet soils, it is an excellent candidate for large rain gardens. This shrub is adaptable to a wide range of soils, but it is not suitable for dry sites. In addition to these functional attributes, Buttonbush offers ornamental value – it’s fragrant, unique-looking flowers that appear in mid to late summer draw the attention of pollinators and people alike. Over time this shrub can attain small tree status. Its trunks become twisted and curved with age, along with an attractive flaking, tan bark giving it an interesting appearance that stands out in winter when the leaves have fallen.

Wildlife Value:

Buttonbush is one of the last native shrubs to leaf out in the spring. Once their oval to elliptical glossy green leaves emerges, they provide food for the larval stage of the hydrangea sphinx moth, royal walnut moth, and titan sphinx moth. In early to mid-July, Buttonbush flowers have prominent round-headed pistils that make them look like pincushions. Bees, hummingbirds, and butterflies appear in the masses and use the flowers as a source of nectar. This plant flowers when many other plants aren’t blooming, which helps pollinators get through lean times until late summer and fall-blooming plants like Aster and Goldenrods start blooming. Russet brown fruits follow the flowers which may persist through winter. Waterfowl, mallards, and other birds eat the fruit and seeds. In their native environment, wood ducks commonly use the plant’s structure for the protection of brooding nests.

Maintenance Tips:

Buttonbush does best in full sun, but it is tolerable of partial shade conditions. It thrives in low-lying areas that may not dry out until late in the season such as bioswales, bogs, and stream banks. Supplemental watering is necessary when planted in full sun locations that dry out. Buttonbush cannot tolerate drought. It is adaptable to different soil types. Don’t panic if the shrub hasn’t leafed out at the same rate as your other plants because this plant is one of the last to leaf out in spring.

Pruning is not usually necessary. If Buttonbush gets too large or unruly, you can shear or rejuvenate the shrub by cutting it close to its base or crown in early spring before new growth emerges. Read more about the Rejuvenative Method of Pruning.

Pests/Problems:

Buttonbush is relatively pest-free and is an easy-to-grow addition to your landscape. It no insects or diseases that cause severe or significant long-term damage. You may encounter Lygus bugs, leafhoppers, or thrips which can cause malformed, stunted, or yellowed leaves. On the plus side, the shrub attracts a plethora of beneficial insects. Notably, the chalcid wasp is drawn to buttonbush because it preys upon thrips, Lygus bugs, and leafhoppers that eat the plant.

This plant rarely suffers severe damage from deer browsing or other animal damage.

Leaf Lore:

Many parts of the plant were used medicinally by native North Americans via decoction to treat a range of ailments. Decoction is a method of extraction by boiling plant material to dissolve the chemicals within the plant material. Decoction of the bark was used by the Chickasaw and Choctaw for making laxatives, curing skin, bronchial and venereal diseases. These tribes also often chewed on the inner bark for treatment of toothaches. The first European settlers used the bark as a prescribed drug for malaria and a substitute for quinine.

The botanical name of Buttonbush is Cephalanthus which originates from the two Greek words “kephalos” which means “head” and “anthos” which means “flower”. This is in reference to the unusual, round shape of the flower heads.

The largest Buttonbush in North America made its debut on the National Register of Champion Trees in 2019. It is 18-feet tall with a crown spread of 17.5-feet and is located in Montgomery, Maryland.

The foliage contains glucosides and can be toxic to humans and many mammals if large doses are ingested. Symptoms include vomiting, convulsions, and muscular paralysis.

Companion Plants:

Common associates of the Buttonbush include American Beech, Sugar Maple, Willow, Black Oak, Musclewood, River Birch, Baldcypress, Switchgrass, Sedge, and Big Bluestem.

Other plants that tolerate wet sites would also do well planted near a Buttonbush. Plants you would commonly find in a rain garden would make great companions as well such as Red Milkweed, Ironweed, Great Blue Lobelia, New Jersey Tea, Glossy Black Chokeberry, or Silky Dogwood. These plants have different bloom times which help support pollinators. Their foliage also has a different texture which adds a nice contrast. Buttonbush can be planted in the lower tier of a large rain garden as it can tolerate water depths of up to three feet.