The intoxicating fragrance and attractive features of this adaptable shrub make it just as appealing near a home’s entryway as in the wild. Erect, wine-red flowers emerge in spring, followed by lustrous, green leaves that change to golden yellow in fall. The plant’s strongly branched form tends to be rounded and slightly wider than it is tall, which, when combined with its tendency to sucker, makes it useful as a windbreak. Often found as an understory shrub or along streams, sweetshrub grows a bit faster and taller (up to 12’) when sited in locations with part sun and rich, well-drained, loamy soils. Growth rate is slower in dry soils and full sun, and the shrub will be shorter with sprawling branches. However, it’s easily grown in a wide range of soils, including clay, and it also grows with a lankier form in shade. For better drainage, amend heavier soils with compost or manure. Sweetshrub tolerates brief periods of flooding, but it struggles in prolonged drought. The plant is largely maintenance free when sited in an area where it’s free to sucker and spread. Plant it 3 to 5 feet from other shrubs to give it adequate room to grow. To shape specimen plants, prune immediately after flowering and remove outer suckers to control spread. Shrubs are easy to transplant, ideally after the leaves have dropped in fall or winter. Rooted suckers may be detached from the main plant and replanted.
There’s a reason sweetshrub is known by so many names mentioning fragrance (Carolina allspice, sweet bubby, sweet Betsy, strawberry bush, and hairy allspice). Beginning in April, a sweet perfume with hints of pineapple, strawberry, and banana permeates the air as the strappy, urn-shaped flowers open before the leaves have emerged. Although each flower loses its fruity scent by the following day, other flowers continue to bloom with their own bursts of fragrance. Once the leaves emerge, the flowers are often hidden, but they continue to bloom and release their scent through May and then sporadically throughout the summer. They give way to drooping, fig-shaped seed pods that persist through the winter. The bark and roots emit a juniper-like scent when rubbed or crushed. The overall intensity and quality of fragrance can vary widely from plant to plant.
Sweetshrub is pollinated by beetles in a process known as cantharophily. Cantharophilous plants, or those primarily pollinated by beetles, have flowers that share common characteristics, such as a bowl shape with exposed sexual organs; no distinction between the petals and sepals; a large and solitary form with radial symmetry; and a strong fruity odor. One study (McCormack, Holt, 1979) found that the flowers’ volatile oils mimic the odor produced by a fungi that attracts beetles. The flowers are shaped to allow beetles an easy entrance. Once inside, it’s difficult for the beetles to escape without transferring pollen. When the flower has been pollinated, the petals draw back and up, allowing the beetles to exit.
Sweetshrub is native to the southeastern United States. In Ohio, the Department of Natural Resources lists it as presumed extirpated, which means no natural populations have been documented since 2000. The genus name comes from the Greek words kalyx, meaning “calyx,” and Anthos, meaning “flower.” The specific epithet means “of Florida.”
Native habitats include mixed deciduous forests, moist woodlands, and banks of streams. Use as a specimen near entryways, patios, or other areas where the fragrant flowers may be enjoyed. Plant in shrub borders, foundations, native plant areas, or use as a specimen plant or privacy hedge. Use boughs in fresh-cut arrangements.
Plant Characteristics:
Most often grows 6-9’ tall and 6-12’ wide.
Achieves best growth in part sun; tolerates full sun and shade.
Prefers rich, well-drained, loamy soils but adapts to a wide range of soils, including clay and lightly sandy. Tolerates brief periods of flooding. Somewhat intolerant of drought.
Reddish-brown, 2” flowers bloom at the ends of short branchlets in spring and occasionally during summer. Petals and sepals (tepals) are straplike. Seed capsules are 1-2” long and turn from green to brown and black. They contain numerous seeds and persist throughout winter.
Slightly rough, ovate to elliptic, dark green leaves have pale gray/green undersides and are 3-6" long and 2-3” wide with slightly angled tips. Fall color is rich yellow, then brown.
Multi-trunked form can be trained to grow with one or several trunks to form a specimen plant. Young stems are reddish, and mature bark is gray.
Reproductive System: Each flower is perfect (hermaphrodite--with both male and female organs) and is capable of self-fertilization. However, it is mainly pollinated by beetles. The flower typically doesn't produce nectar, which encourages beetle pollination.
Wildlife Value:
Host plant for larvae of double-banded zale, oblique-banded leafroller moth, and saddleback caterpillar moth. The dense branch structure provides cover and nesting for a variety of birds and small mammals.
Medicinal, Edible, and Other Uses:
Native Americans used sweetshrub as an antispasmodic, a disinfectant, and a diuretic.
The bark is sometimes used as a cinnamon substitute.
Sweetshrub produces an essential oil, calycanthus, which is used in perfumes and other cosmetic products. Parts of the plant are used in potpourri, which may be placed in drawers and closets to keep clothes smelling fresh.
The trunk and branches have been used to create arrows, baskets, and other crafts.
Caution: The flowers and seeds are poisonous to humans, pets and livestock, especially if eaten in large quantities.
Resources:
North Carolina Extension: https://plants.ces.ncsu.edu/plants/calycanthus-floridus/
The Spruce: https://www.thespruce.com/carolina-allspice-growing-guide-5213158