My favorite winter scene is branches of bright green holly leaves with sparkling red berries against fresh winter snow. Holly is a great addition to the landscape, but careful consideration must be given its planting.
Several holly species will provide colorful fruit for three to six months of the year, but fruit persistence depends on the bird and squirrel population in the area. Plants with yellow berries are often ignored by birds or are eaten after red fruits are gone.
Holly plants are dioecious, meaning that both male and female plants are needed to ensure fruit production, although only the female produces fruit. It is important to have male and female plants that are closely related and flower at the same time. How do you know the sex of a plant? Male and female flowers have different parts. For some of us, this may be a little difficult to see, so we must rely upon retailers to correctly mark the plants. Most cultivars have sex-appropriate names, such as “China Boy.”
One of the better-suited hollies for our landscape conditions is winterberry, Ilex verticillata. Winterberry is a deciduous holly that is hardy to zone 3. Another bonus: This native plant is fairly resistant to pests and disease. The leaves, which are rounded, will remain on the plant into the late fall. The plant begins to display red berries, which can last several months, in September. Cultivars vary in height from 5 to 10 feet. This species is a good selection for shrub borders or screening. Female plant selections with red fruit include Red Sprite, Winter Red, and Harvest Red. Winter Red can grow 8 or 9 feet tall and wide, whereas Red Sprite grows just 3 to 5 feet all. Aurantiacum, an orange-fruited winterberry, reaches 5 to 8 feet tall. A good male pollinator is Jim Dandy Dwarf.
Blue holly, Ilex x meserveae, is a blue-green broadleaf evergreen variety that grows 8 to 15 feet high. This group has several great lady selections, including Blue Princess, Blue Maid (Mesid), and Golden Girl (Mesgolg). As the name implies, Golden Girl produces vibrant golden fruit. Male pollinators for these ladies include Blue Stallion (Mesan) and Blue Prince. Most of these selections grow 4 to 6 feet tall.
A fast-growing hybrid, more drought-tolerant than the blue hollies, is Ilex rugosa x cornuta China Boy and China Girl.
American holly, Ilex opaca, is a pyramidal broadleaf evergreen that grows 25 to 50 feet tall. Hardy to zone 5, this species will not tolerate cold, harsh winds and needs a protected location in which to grow.
Inkberry holly, Ilex glabra, produces a black fruit, and the dark-green leaves resemble those of boxwood. The Compacta cultivar is an excellent foundation plant, growing 3 to 6 feet tall with about the same spread.
As I’ve noted many times in this column, the ultimate size and shape of a mature plant are important considerations. Plants need ample space in which to grow. Hollies must be planted in partial shade, protected from winter sun and wind. They prefer a moist, organic, well-drained soil. Although hollies will tolerate alkaline soil, they prefer an acidic soil. Select cultivars that are hardy in zone 5. Be sure plants get ample moisture during dry periods, especially going into winter.
Keep mature plants at a manageable size and shape by pruning them in late fall or early winter after they have been established for several years (new plants resent pruning). Pruning is good not only for your holly but also for your home décor: Cut branches make wonderful holiday decorations. Put them an outdoor container or on your fireplace mantel.
Jennifer Fishburn is a horticulture educator with the University of Illinois Extension Sangamon-Menard Unit. Contact her at www.extension.uiuc.edu/Sangamon.