By Jim Lakin, M.D., Master Gardener
We have some wonderful marsh lands on our property. Among the Giant Blue Lobelias and the Cardinal flowers there’s a delightful shrub that stands out, the Buttonbush (Cephalanthus occidentalis). This is a native perennial plant to much of the Eastern North America from Nova Scotia to Minnesota, south to Florida and East Texas. You’ll find it in a range of wetland habitats including swamps, floodplains, mangroves, around ponds and margins of streams and even moist forest understories. It grows as a deciduous shrub or small tree, running from three to ten feet in height. It has glossy green leaves which appear in the late spring. Its unique fragrant white to pink bloom, shown in the first picture, gives it its common name. Buttonbush usually blooms from June through September although this period may be shorter further north. It was introduced commercially in 1735 as a source of nectar for commercial honey production. Thus, it’s other common name, Honey Bells.
Buttonbush forms an important link in the wetland ecology. A number of waterfowl eat the seeds and wood ducks use the plant as nest protection. We’ve had a pair in our pond for several years that seem to regularly avail themselves of our buttonbushes building material. Deer browse the foliage which surprisingly is poisonous to livestock. Darn deer eat anything! A number of native as well as honey bees feed on the nectar as do hummingbirds. The plant acts as larval host to Titan Sphinx, Walnut and Hydrangea Sphinx moths. It can be used in butterfly gardens, as a naturalizing plant or to control erosion in difficult, moist areas. It’s great for naturalizing.
To grow Buttonbush, select a fairly moist environment. As you might imagine it has a pretty high water requirement even though it likes shade to part shade. It is a spreading multi-branched shrub with an irregular crown which produces balls of white flowers resembling pincushions. As it can get a bit lanky, plants in a more formal setting might need to be pruned from time to time. It is a rapid grower and spreads by suckering. It is said to be hardy from Zones 5 to 11 although a number of plants do just fine in Zone 4. For Minnesota gardeners it might be wise to consider planting in a protected area and mulching in the fall at least for the first year or two. Getting a local specimen is also important.
Buttonbush is an otherwise hardy ornamental perennial. It’s a native that is an attractive addition to any moist shady area.