The southern United States is generally defined as the area south of the Mason-Dixon Line and includes states as far north at Virginia and as far south as Florida and Texas. According to the U.S. Department of Agriculture plant hardiness zone map, this region represent zones 7 and above. Though temperatures can drop to 0 degrees F, these states usually have mild winters, though the northern portion is susceptible to freezes. Plants that grow well in the winter in this region add color and interest to a landscape during cooler weather.
The Autumn Camellia (Camellia sasanqua) is an evergreen shrub or small tree that provides screening or an informal hedge and produces lots of flowers in late fall to early winter. Blooms do not last long, and multiple plants are required if you want color for several months. Hardy from zones 7 to 10, the Autumn Camellia can grow to 12 feet. The "Apple Blossom" cultivar has white flowers blushed with pink; the "Kanjiro" cultivar has rose-colored double-blossoms; and the "Yuletide" cultivar has deep red blooms. This variety tolerates full sun better than most other camellias, but in the deepest part of the South should be planted in part shade. Autumn Camellia requires regular water.
Hellebore (Helleborus) is a perennial evergreen plant that grows in many varieties that bloom at different times. Hardy in zones 6 to 9, it blooms throughout winter and spring, even in the coolest climates. The Corsican Hellebore (H. argutifolius) has large, chartreuse flowers in late fall to early spring in mild winter areas, while the Christmas Rose (H. niger) produces white-green flowers that age to purple beginning in December. In general, Hellebore is a shade-loving plant and should be planted in partial to full shade and get regular water.
Tea Viburnum (Viburnum setigerum) is a small tree or shrub that can grow to 12 feet and produces flower clusters in late winter. Hardy in zones 5 to 7, this plant has a bare stem, but the head of the plant has blue-green leaves up to 6 inches long that age to purple before dropping in the fall in coldest areas. Tea Viburnum has clusters of white flowers in spring before giving way to small, scarlet-colored fruit. This plant grows best in sun to partial shade, though it can do well in heavily shaded areas in warmer regions. Tea Viburnum needs average water and grows in most soils. It will attract butterflies and birds to the garden.