Sweet Box Evergreen Shrubs
Sweet box is the common name for a group of evergreen shrubs and groundcovers in the Sarcococca genus. The plants get their common name because they are members of the boxwood (Buxus spp.) family, Buxaceae, and because they have small, dark green leaves, similar to those of boxwood. They also have sweetly scented flowers, so they’re sometimes called fragrant sweet box.
Sweet box grows in U.S. Department of Agriculture plant hardiness zones 6 through 9. It has shrub forms that reach up to 5 feet tall and wide, as well as 2-foot-tall groundcover forms that spread by underground rhizomes. All have fragrant flowers. The two most common shrub forms, Sarcococca confusa and Sarcococca ruscifolia, are nearly identical and often are sold as the same plant, but Sarcococca ruscifolia is slightly smaller, reaching 3 to 4 feet tall and wide and slightly less hardy, growing in USDA zones 7 through 9.
Flowers and Fruit
One of the boons of sweet box is that it flowers in February and March when little else is blooming, scenting the air around it with sweet fragrance. The flowers are tiny and white and often are hidden by the evergreen foliage, but the scent can make you swoon. Berries develop after the flowers and ripen in late summer to early fall. Sarcococca confusa’s berries start red and turn black. Sarcococca ruscifolia’s berries stay red, another difference between the two shrubs. The groundcover forms bear black berries. Deer and rabbits leave sweet box alone, but the berries are attractive to birds.
Sweet box is a valuable plant for gardeners not only because of its welcome winter blooms but because it is drought tolerant and thrives in part to full shade. Plant it in well-drained, acidic soil that has been amended with plenty of organic matter. Water regularly to establish a strong root system and drought tolerance. Prune in spring, after flowering, if you want a more regular shape than sweet box’s dense, arching habit.
Because of its fragrant flowers, sweet box is a good choice to plant near a walkway, porch or foundation. It can be used to block the view of utilities, vents and air-conditioning units. Because there are few choices of flowering evergreen shrubs for shade, sweet box is especially useful for woodland gardens and as a structural plant for the shady border. Because of its dark green foliage, it acts as a foil for plants with brighter foliage and flowers. It will form a natural espalier if planted against a wall and takes shearing well when used for hedging. The groundcover forms, such as Sarcococca hookeriana var. humilis, create thick drifts of leathery foliage that suppresses weeds.
Since 1981 Janet Bayers has written on travel, real estate trends and gardening for "The Oregonian" newspaper in Portland. Her work also has appeared in “Better Homes & Gardens,” “Traditional Home,” “Outdoor Living” and other shelter magazines. She holds a Master of Arts in linguistics from Michigan State University.