Holly plants (Ilex spp.) are a diverse lot, American holly being just one of many types. Ilex is among the few plants that can grow in all USDA plant hardiness zones (or in all 50 U.S. states). Holly trees and shrubs are sometimes deciduous, but more often evergreen. The plants come in many shapes and sizes, ranging from spreading dwarf shrubs 6 inches in height to trees 70 feet tall. Their shapes vary from rounded to columnar to pyramid-shaped.
Uses for Holly in Landscaping
Gardeners use the versatile holly plant in a number of different ways. Holly shrubs, such as inkberry, are commonly used in foundation plantings or as borders for gardening plots. Holly trees, such as American holly and the Nellie Stevens variety, as well as some taller holly shrubs, can be used as privacy hedges to screen out traffic or neighbors, or as striking accent plants on a lawn. As broadleaf evergreens, hollies make ideal privacy screens around pools because there are no leaves or needles to clean up.
Holly is perhaps most commonly used to add visual interest to color-starved landscapes in winter. And, of course, holly is prized for Christmas decorations, both indoors and outdoors.
Bird watchers, take note: Several bird species are attracted to holly shrubs, including thrushes and blackbirds. According to the USDA Forest Service, holly berries are also eaten in winter by:
- Wild turkeys
- Cedar waxwings
- Mourning doves
American and English Holly
The hollies with which we are most familiar are English holly (Ilex aquifolium) and American holly (Ilex opaca). This is due to their large size, striking evergreen foliage, and (especially in the case of English holly) long-time association with the winter holiday season. Some varieties of English holly plants grow quite tall, so be careful what you buy. Ilex aquifolium 'Ferox Argentea' reaches a moderate height of 15 feet, with a spread of 8 to 10 feet. It grows in zones 6 through 9.
American holly trees are native to the southeastern United States and many states along the Atlantic coast. The USDA Forest Service, establishing the northern end of American holly's range, remarks that the Pilgrims noted American holly's presence in Massachusetts when they landed in 1620. An example of American holly is Ilex opaca 'Mac's Prince,' which grows in zones 5 through 9. It reaches a height of 15 to 30 feet, with a spread of 10 to 20 feet.
A pyramid-shaped evergreen tree with spines on its foliage, American holly blooms in May or June (depending on where you live). It is a deer-resistant tree. Grow it in well-drained soil, but keep the soil moist. While it can grow in partial shade, you will achieve denser growth if you give it full sun. American holly is a slow grower and typically matures to a height of 30 feet (but may be taller in the wild). Its prickly leaves are a dark green color. Most types bear red or orange berries.
Cultivars of American holly include:
- 'Jersey Princess' (a female cultivar)
- 'Jersey Knight' (a good male pollinator to use with 'Jersey Princess')
- 'Canary,' which has yellow berries instead of red ones
All holly trees and shrubs are dioecious, meaning there are distinct male and female plants. So if you want your hollies to grow berries, you must plant both female and male plants together. Typically, you need to plant a male within 30 to 40 feet of females in order for the latter to yield berries.
Little Red Holly
Little Red holly (Ilex x 'Little Red') is an example of a medium-sized holly plant. Little Red's dense growth and compact nature (5 feet by 5 feet) make it useful for privacy screens in areas where taller hedges would not work. This evergreen produces attractive red berries and has a moderate growth rate. Little Red can be grown in full sun or partial shade, and it likes well-drained soil with an acidic pH. In fact, all hollies prefer to grow in acidic soils, which is why in nature they do so well in oak forests. Little Red is cold-hardy to zone 6.
Winterberry holly (Ilex verticillata) is one of the deciduous types of this group. Another characteristic that sets it apart from other common hollies is its tolerance for a variety of growing conditions. While most holly cultivars require well-drained soil, winterberry holly will perform just fine in either well-drained soil or wet soil. Winterberry holly loses its foliage before Christmas, but that is a good thing: With no leaves to obstruct the view, the plant's prized red berries take center stage.