Plant of the Month - Archive
Winterberry By Dave Dister
Among the more long-lasting and spectacular red-fruited shrubs, the winterberry (Ilex verticillata) is a natural inhabitant of wetland edges, marshes, swamps, pond margins, and streamsides. This shrub may grow to 12 feet in height and is rather densely branched. Winterberry leaves are simple, with toothed edges, elliptical in shape, and 1 to 3 inches in length. The leaves turn black after frost - a rather unique character. The stems are olive-brown to purplish-brown, and have conspicuous lenticels - corky elevated spots that are believed to aid in air exchange. The presence of lenticels may be especially beneficial for those plants that grow in oxygen-poor habitats (i.e., wetlands and other habitats with high water tables). The familiar common elderberry (Sambucus canadensis) also grows in wet habitats and has quite large lenticels.
Winterberry will produce root suckers, and thus can spread to form extensive clones in suitable habitat. It also prefers acidic soils with a pH of 4.5 to 5.5 (7 is neutral, while 8 to 10 is alkaline or basic). This plant grows throughout Michigan, and it occurs from Newfoundland to Minnesota and south to Georgia and Mississippi.
Winterberry is in full bloom in mid-summer (May-August) across its range, and the small greenish-yellow flowers are insect pollinated. Unusual among woody plants, this species has male and female flowers on separate plants, and only female plants bear the colorful fruits (drupes), which can be so numerous as to obscure the supporting twigs. Of course, this scarlet splendor is not achieved until the 1/4 inch berry-like fruit ripens in autumn. Winterberry is sometimes referred to as "deciduous holly" as it is a member of the holly family that uncharacteristically sheds its leaves each fall. Other common names include coralberry, black alder, and Michigan holly.
Winterberry can be quite outstanding in early winter, when the red fruit is covered with snow. Fortunately, winterberry is often available in the nursery trade for those homeowners that have moist soil conditions and a fair amount of sun. There are many cultivated varieties of this attractive shrub, including those with yellow or orange fruits, while the native forms are (unfortunately) often less available. Of course, the conspicuous fruits are readily eaten by various birds and other wildlife. So for those wanting to provide both vivid color in their landscape and a food source for birds into early winter, winterberry is an excellent choice.