(Editor's Note: This article was originally published on November 30, 2009. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
For regions that don't have a lot of snow cover and freezing temperatures in winter, the gardening season can be extended throughout winter by careful choice of winter interest plants and shrubs such as hellebores, snowdrops, aconites, dogwoods with their decorative bark, witchhazels, daphnes, wintersweet, camellias and sweet box. Any plant that flowers in the dead of winter has to be a valuable addition to the year-round garden!
One such valuable winter performer is Sarcococca. Try to find a spot close to the house for Christmas box, or sweet box. Under a window which you might open on a sunny day. Or close to a path to the greenhouse or shed, or near a seating area. Christmas box is a smallish evergreen shrub native to Asia. The leaves are dark shiny green, leathery and pointed and in winter the stems bear many very small white flowers almost hidden underneath the leaves, which are followed in summer by red or black berries.
Quite an unassuming plant at first glance, but once you smell the strong, delicious honey perfume which is produced by the flowers, you will want to have this plant in your garden. I remember a visit to Harlow Carr garden in Yorkshire which is just as wonderful in winter as it is in the height of summer. I was literally stopped in my tracks by the scent from a sweet box plant and retraced my steps until I found the plant that had such a strong scent.
There are several winter flowering shrubs that produce strongly scented flowers such as wintersweet, witchhazel, mahonia and Viburnum bodnantense. They are thought to do this to attract pollinating insects. They in turn will attract birds to your garden. Any of these shrubs are worth a spot in your winter garden, and you can dress them up with a clematis in summer if you choose one from the group that needs pruning back to the base in winter.
The Sarcococcas are very good choices for a small garden as they are dense evergreens which reach about 2 or 3 feet high by as much across, so they will fit into pretty much any garden situation where space is short. Related to the common box, Buxus, they are hardy in USDA zones 7 to 9. They can be used as an alternative to common box as hedging or in parterres. They also adapt well to containers, being fairly small, so can be moved to a more prominent spot in winter, then moved again to make way for more showy plants in summer.
Sweet box is a slow growing shrub, taking 10 years or more to reach maturity. They require little pruning. A situation in partial shade will suit them well. The shrubs are ideally suited to mass woodland planting, particularly the suckering types and can be used as ground cover. A rich organic soil is one in which they will thrive, but they will also do well in poorer soils in quite deep shade. They are rarely troubled by pests or diseases. The plants can be propogated either by division of the rhizomatous species or hardwood cuttings taken in autumn.
The genus consists of around 15 species.
The more commonly grown ones are
Sarcococca confusa - reaches about 6 feet at maturity. Flowers are followed by long lasting black berries.
Sarcococca ruscifolia var chinensis - vigorous with large slender leaves, ideal for groundcover, less hardy.
Many thanks to Galanthophile for use of some of the photos in this article. Other photos are my own.