In today’s post, we’re wrapping up our four-part series highlighting the list of “Great Trees for Landscapes” selected by our staff. As we head into the winter, it’s only appropriate that we focus on the trees that really shine this time of year: the paperbark maple, green hawthorn, river birch and American holly. Whether for their handsome bark, evergreen leaves or persistent colorful fruits, these trees are all great choices to add some winter interest to the home landscape.
Paperbark Maple (Acer griseum)
Mature Size: 20 – 30′ high and 15 – 20′ wide
USDA Hardiness Zone: 5 – 7
Light Requirements: Full Sun to Part Shade
The paperbark maple is one of those trees that we field a lot of questions about at the Arboretum. It’s distinctive, cinnamon-colored bark exfoliates in beautiful curls that can cling to the tree for some time, catching the light in a way that instantly draws your eye from across the garden in the wintertime — or any time of year, for that matter! In the growing season, its bluish-green trifoliate leaves may not look particularly maple-like to the casual observer, but once you get to know this handsome specimen tree, there’s no mistaking it for anything else.
Native to the forests of central China, the paperbark maple feels right at home here in Western North Carolina, but unlike some other exotic maple species that have a tendency to escape cultivation, you can rest easy planting it near a forested area, as this species produces very few viable seeds. What it lacks in ease of propagation, this stunning tree more than makes up for in ornamental value and ease of care. In the fall, its leaves transform into variable hues of orange and red that can be quite brilliant, offering a lovely autumnal prelude to its stunning wintery bark display.
Green Hawthorn (Crataegus viridis)
Mature Size: 20 – 35′ high and wide
USDA Hardiness Zone: 4 – 7
Light Requirements: Full Sun to Part Shade
As you walk through the Arboretum’s gardens this time of year, you’re almost sure to spot a cedar waxwing or two flocking to the branches of the many fall-fruiting trees and shrubs we have planted here. But among them is a standout in my mind: the green hawthorn. The tree’s bright red fruits — or pomes — can persist on its bare branches well into the winter months, providing a striking pop of red that really shines in the landscape. But this is by no means a one-season plant!
In the late spring, fragrant white flowers appear in small clusters across the tree’s spreading crown. And although you might not immediately notice the similarity in its flowers, the green hawthorn is actually in the rose family — the Rosaceae. Perhaps the fruits’ similarity to rose hips is a better indicator of this botanical relationship, but so too is the occasional, inch-long thorn that can appear along its branches! Unlike other hawthorns, however, Crataegus viridus is largely spineless.
This handsome native tree’s shallowly lobed leaves turn a pleasant purple or red in fall, and on mature specimens, the winter show extends beyond the ornamental fruits to include bark that exfoliates to reveal orange hues beneath, which more than secures it a spot on any list of stars of the winter garden. At the Arboretum, we grow the variety ‘Winter King,’ which offers larger fruits, improved fall color and better disease resistance. What more could you want from a tree with multiple seasons of interest?
River Birch (Betula nigra)
Mature Size: 70′ high and 60′ wide
USDA Hardiness Zone: 3 – 9
Light Requirements: Full Sun to Part Shade
Although it was probably written with the paper birches of New England in mind, whenever I walk past a towering river birch like the one located adjacent to the Arboretum’s Plants of Promise Garden, I am nonetheless reminded of the famous poem by Robert Frost. While it may not be quite as showy as its northern cousin, the river birch is more than deserving of its own poetic feature. It is a wonderful choice for gardeners in more southern climes to enjoy that beautiful, flaky birch bark that peels away from the tree in sheets resembling pinkish-cream to gray-brown paper. Leathery, toothed, diamond-shaped leaves complete the package and provide a spot of yellow in the autumn landscape.
The river birch is a workhorse of a tree, and is perhaps the most adaptable of the birches. It can grow upwards of two feet in a year — especially in moist areas — which makes sense for a tree whose common name includes the word “river.” In nature, it can be found growing alongside streams and in floodplain environments. It often develops as a multi-trunked specimen with a unique habit and can reach rather substantial heights. Coupled with its handsome bark, these features make the river birch a welcome feature in the winter garden and certainly earn it a place on this list.
American Holly (Ilex opaca)
Mature Size: 15 – 30′ high and 18 – 40′ wide
USDA Hardiness Zone: 5 – 9
Light Requirements: Full Sun to Part Shade
No matter the time of year, if you’ve visited the Arboretum, you’ve no doubt taken note of the beautiful hedge of American hollies that defines the boundary between our core gardens and Grand Garden Promenade. As the name would suggest, these large shrubs to midsize trees — depending on the variety grown and how they are maintained — are native to the American East, including our region. Although there are American hollies growing across the Arboretum, the varieties ‘Satyr Hill’ and ‘Miss Helen’ were chosen to provide the backbone of our garden spaces for their exceptional landscape performance, disease resistance and conical habit, as well as for the bright red berries that they produce in the fall, which persist on the plants into winter. That said, there are more than a thousand varieties of American holly out there, including some with orange or yellow berries!
Not only are these berries highly ornamental, but they are readily consumed by birds and other wildlife. Interestingly, though, not all American hollies produce fruits. They are a dioecious species, meaning their male and female flowers are borne on separate plants. You must have the two growing near enough to each other for the females to set fruit — with a little help from pollinator insects like bees, of course! Although the blooms provide another season of wildlife value for these insects in the summer, we should be the ones thanking them for their vital role in providing us with the beautiful fruits that will end up in centerpieces and wreaths as our holiday decorations this time of year.
As a star of the winter garden — and winter décor — the American holly has more than earned its spot on this list of Great Trees.
If you want to see beautiful, mature American hollies — or any of the trees featured in this post — you can find them growing across The North Carolina Arboretum! Or to see containerized specimens of all 15 “Great Trees” gathered in one spot, be sure to check out our “Great Trees for Landscapes” popup exhibit, which will remain along the Grand Garden Promenade through the winter months. We think there’s a spot for more of these “Great Trees” in home landscapes and hope you’ve enjoyed this resource.