Shrub of the Month: Ilex verticillata, Winterberry

Posted: February 16, 2012

January is one of the bleakest months in the Pennsylvania landscape with its cold, snowy weather and gray skies. Fortunately, there are shrubs that brighten winter days with colorful fruits or stems that are suited to every landscape. One of the best is our native winterberry, Ilex verticillata.

While most trees and shrubs do not shine in winter, winterberry hollies are at their best while the rest of the landscape looks barren. Unlike evergreen hollies, winterberries are deciduous. The lack of leaves makes the prolific display of red fruits that much more dramatic.

While there are other shrubs that produce berries into the fall and winter landscape, they simply do not have the staying power of winterberries. Callicarpa japonica (Japanese beautyberry) fruits are a lovely, unusual amethyst color, but they shrivel and drop off by November. Many Viburnum species have impressive red or blue fruit, but birds devour them as winter arrives. Winterberry fruits are eaten by many species of songbirds, waterfowl and game birds, but they have a relatively low fat content. That means they are often not eaten until late winter, when higher fat content food sources have been exhausted.

While winterberry flowers are small and not particularly showy, they are very popular with honeybees and other pollinators. Fall color runs from a brief yellow to non-existent, but the display of fruit more than makes up for that shortcoming. Remember that hollies are dioecious, with male and female flowers on separate plants. One male plant can pollinate five to ten female plants (some sources suggest one male for every twenty female plants, others one male for every three to five females), and should be planted in reasonable proximity to the females. It is also important to choose the male pollenizer that blooms at the same time as the female winterberries you are planting. The list from Walter Reeves will help in choosing the correct male pollenizer.

Winterberries are found all along the East Coast, and west to Missouri. They are often found in swampy areas, or along rivers and streams where they are subject to periodic flooding. This makes winterberries ideal for rain gardens, but they also thrive in ordinary garden soil. They prefer full sun to partial shade and moist, acid soil that has good organic matter content. Winterberries typically grow eight to twelve feet tall with a similar spread, although there are dwarf cultivars. They are a suckering species, which makes them good at stabilizing hillsides.

Numerous cultivars of winterberry hollies are available, including hybrids with Japanese winterberry (Ilex serrata). There are dwarf selections as well as cultivars with gold or orange fruit. Some of the best include:

  • I. verticillata ‘Red Sprite’, a dwarf selection that grows with a rounded habit to three to five feet tall. Valued for good fruit production and persistence. ‘Jim Dandy’ and ‘Apollo’ will pollinate.
  • I. verticillata Winter Red® grows eight to nine feet tall with a comparable or greater spread. Valued for heavy fruit set and persistence. ‘Southern Gentleman’ and ‘Apollo’ will pollinate.

winterberry at Phipps