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American Holly Adds Decorative Touch to Your Garden... and a Home for Birds
Holly, with its brilliant red berries, is an icon of the holiday season. But adding hollies to your garden helps feed and house birds, too.
by Rick Lewandowski - 1/5/2009
For many of us who draw on the garden for both inspiration and utility, the evergreen American holly (Ilex opaca) shines as both a garden companion and a celebrated icon of the holiday season just past.
It’s said that upon arriving on the shores of North America following their arduous journey across the Atlantic Ocean, early 17th-century European newcomers were greeted by the luxuriant evergreen foliage and brilliant red fruit displays of enormous American holly trees growing throughout the maritime forests. The American holly, though foreign to them at the time, fondly reminded these travel-weary early settlers of their beloved English holly or Christmas holly (Ilex aquifolium), left behind in a homeland now far away.
Whether this story is fact or legend, American holly has certainly become deeply ingrained in the American Christmas tradition as a theme in holiday decorations. Despite this fact, American holly has been generally overlooked for popular landscape use in favor of other evergreen plants. However, it is a remarkably adaptable tree, with many outstanding landscape attributes that rank it among the elite of evergreen aristocrats worthy of wide garden use, particularly in our region.
If you enjoy hiking, you’ll likely encounter American holly throughout the eastern U.S. as a frequent understory tree in acidic, well-drained soils, particularly the further south you travel. From Delaware and New Jersey north to New England, American holly is most commonly encountered in coastal or maritime forests where it grows in acidic, sandy soils.
In nature, American holly frequently grows as an understory tree – sometimes reaching 60 feet tall or more – in the shadows of large deciduous trees, including red maple (Acer rubrum), American beech (Fagus grandifolia), tulip-poplar (Liriodendron tulipifera), black gum (Nyssa sylvatica), Southern red oak (Quercus falcata), water oak (Quercus nigra), and red oak (Quercus rubra). In the dimly lit forest understory of these large trees, American holly is also found growing with hornbeam (Carpinus caroliniana), American dogwood (Cornus florida), mountain laurel (Kalmia latifolia), sweet-leaf (Symplocos tinctoria), and highbush blueberry (Vaccinium corymbosum), along with many herbaceous species.
At Home in the Garden
In the garden, American holly is adaptable and accommodating, growing with many of the companions mentioned above as well as others. In the shade it tolerates considerable stress and root competition from other plants. An added advantage of American holly, though, is that it is also quite adaptable to sunny, dry garden conditions. Over the years we’ve successfully grown American holly under a wide range of garden conditions and, with the possible exception of wet soils or high pH soils, it has performed extraordinarily well, remaining carefree and beautifully evergreen.
There is no doubt that American holly grows more slowly than many evergreen trees, and patience is part of the gardener’s reward for a beautiful, long-lived tree. It typically grows about a foot or so each year under normal garden conditions.
Over time, though, American holly will become a medium-sized evergreen tree ranging from 25 to 40 feet tall and 10 to 15 feet wide, with a tidy, upright-pyramidal habit. If left undisturbed, American holly will also retain a skirt of foliage-laden branches to the ground.
A Specimen Tree
Because of its mature size, American holly makes a fine evergreen specimen tree in the garden, or a border plant for screening along the property edge. If you are fortunate enough to have a larger property, American holly also can be incorporated as an understory tree in the woodland to bring winter interest to the garden. Finally, if you are looking for a plant to use as a hedge, American holly is an excellent choice. It is quite adaptable to pruning and remains dense.
Amazingly, more than 1,000 cultivars of American holly have been selected; yet, only a handful are found in commerce today. Some notable cultivars include ‘Jersey Princess’ (lustrous dark foliage and good red fruit), ‘Old Heavy Berry’ (consistently large quantities of bright red fruit every year), 'Canary’ (bright yellow fruit), ‘Maryland Dwarf’ (3-feet tall, broad-spreading shrub without fruit), ‘Miss Helen’ (dark red abundant fruit), ‘Halcyon’ (narrowly pyramidal with abundant red fruit), and ‘Satyr Hill’ (large red fruit).
To truly appreciate the beauty and diversity of these hollies, though, you need to see them for yourself. Here’s an idea – walk off the results of all your “holiday feasting” by visiting one of the outstanding public gardens in the region that have stunning specimens of American holly in their landscapes. Longwood Gardens in Kennett Square, Pa., Scott Arboretum of Swarthmore College in Media, Pa., and the Morris Arboretum of the University of Pennsylvania in Philadelphia are particularly notable for their stunning American holly plantings. Perhaps you’ll be inspired to try one of the less-common cultivars after you’ve seen the fine specimens in these gardens.
Since bright winter fruit display is a major selection-criteria for garden use, it is important to remember that, like all hollies, American holly has female (fruiting) plants and male (pollen-bearing) plants. In order for female plants to develop fruit, a male American holly should be growing nearby to pollinate the female cultivar and ensure good fruit-set. In the case of American holly, there are only a few male cultivars; fortunately, most male cultivars seem to have a long blooming period, effectively pollinating a wide range of female cultivars. Consult with a local nurseryman about this when you buy a holly, though.
Shelter and Food
Because of its prickly evergreen foliage and dense habit, American holly provides excellent cover, particularly in winter, to a broad range of small mammals and birds. Additionally, its berries serve as a major food source. According to several wildlife resources, a variety of migratory and non-migratory birds eat American holly berries, including cedar waxwings, American goldfinches, robins, cardinals, wood thrushes, rose-breasted grosbeaks, gray catbirds, and nearly 20 other bird species.
American holly is truly a pleasure to have in the garden, especially during winter, with its lustrous evergreen foliage and wondrous fruit displays. And, don’t forget, not only are you enhancing the beauty of your garden, you’re providing a home and food for wildlife as well!
The American Holly is Delaware's State Tree
Did you know that American holly is the State Tree of Delaware?
During the early years of the 20th Century, the abundance of American holly in Delaware led to the establishment of a major export industry in the state. By the 1930s, Delaware was the leading producer in the United States. Holly products from Delaware were shipped throughout the U.S., and even exported to other countries. In time, the southern part of Delaware, in particular Milton, became known as "The Holly Capital of the World."
With such visibility and importance to the state of Delaware, the American holly was adopted as the official State Tree of Delaware by an Act of the Delaware General Assembly, which was signed by Governor Richard C. McMullen on May 1, 1939.
(A version of this article by Rick J. Lewandowski, director of Mt. Cuba Center, first appeared in the Wilmington News-Journal newspaper. For more information about Mt. Cuba Center, visit www.mtcubacenter.org.)