By Dawn Pettinelli, UConn Home & Garden Education Center
Looking for a splash of color in your yard amid winter’s dreary landscape? Check out one or more of the many winterberry (Ilex verticillata) cultivars. This deciduous member of the holly family sports bright, shiny red berries from early fall through late winter. Branches may be cut and used in holiday arrangements.
Winterberry can be found growing throughout eastern North America from Canada down along the east coast and west to Texas. Look for the brilliant red berries when driving past marshy areas in particular. While winterberry will grow in well-drained soil, it is a great candidate for areas that stay moist and aren’t particularly well drained. These plants naturally occur in forested wetlands as well as along the banks of streams, ponds or other water sources.
There are several factors to consider when selecting a winterberry bush for your yard. One of the most important is the mature size of the plant. Cultivars are available that vary from dwarf, 4-foot, compact plants to 15-foot, more rangy specimens. ‘Red Sprite’ and ‘Berry Poppins’ are two red-berried, compact cultivars. ‘Winter Red’ and ‘Sparkleberry’ typically top 10 feet. Check out suggested cultivars for Connecticut with the UConn Plant Database (https://plantdatabase.uconn.edu/). While initially slow growing, winterberries may eventually form clumps through suckering and depending on the cultivars, may form dense stands if allowed.
The berries on most cultivars are a brilliant red. There are, however, some that have gold or orange fruits. ‘Goldfinch’ boasts golden yellow berries while both ‘Aurantiaca’ and ‘Afterglow’ offer delightful orangey fruit.
Do realize that plants are dioecious, meaning that individual plants may be male or female. Only the female plants produce berries. The male plants supply the pollen to fertilize the female’s flowers so that berries are produced. One male plant can fertilize at least 10 females if located within 50 feet or closer. Look at tags so a compatible male cultivar is chosen. Appropriate pollinators should be listed on nursery tags.
Unless plants are in bloom or have berries, it is not possible to tell males from females, but they should be marked on their tags at the nursery. When in bloom, the female flowers have tiny green immature berries in the center while the males have fluffy, yellow, pollen-bearing anthers. Occasionally the female flowers have non-pollen bearing anthers, probably effective is luring pollinators to fertilize their flowers. Although not common in Connecticut, one native species of cellophane bee, Colletes banksi, is a specialized pollinator of winterberry.
Winterberries do best in full sun to partial shade. The shadier the site they are grown in, the fewer blossoms and berries they will produce. Being native New Englanders, they prefer acidic soils rich in organic matter. If your soil pH is between 5 to 6.5, plants should happily grow. Once plants are established, only minimal fertilization is usually required. For the first few years, about a cup of a complete organic or synthetic fertilizer could be lightly worked into the soil surrounding the plant each spring.
Plants can be used in foundation plantings, as a hedge, in rain gardens and when setting up areas attractive to wildlife. Not only are pollinators attracted to the flowers but over 48 species of birds feed on the berries, typically after they soften following periods of freezing and thawing.
Pruning can be tricky and is best kept to a minimum so selecting the right sized cultivar for your particular site is crucial. Winterberries have an upright growth habit but may sucker. They bloom on old wood meaning the flower buds that open in the spring were formed last fall. If grown as a multi-stemmed shrub, a few stems can be removed if plants seem crowded.
Complaints about little or no berry production may be due to lack of a male pollinator, too much shade, young plants that have not established a good root system, improper pruning or excessively dry conditions. In general, winterberries are rewarding, easy to grow shrubs that make quite the impact when little else in the landscape stands out.
For questions about selecting or growing winterberries or for other gardening queries, contact the UCONN Home & Garden Education Center, toll-free, at (877) 486-6271, visit their web site at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension Center.
