How To Pick A Native Tree For Your Yard
By Cathy Jean Maloney
The Morton Arboretum
Flower fads may come and go, but when it’s time to select a tree, you want one that will enhance your garden for many years. It should thrive and grow more beautiful despite the vagaries of weather, pests, diseases and the occasional misguided football spiral.
What you want is a native tree. Well adapted to our region’s growing conditions, native trees will beautify your landscape throughout the decades. Kunso Kim, the Morton Arboretum’s Assistant Director of Collections, names his four favorites.
“Bur oak is a symbol of longevity,” he says of this icon of the prairie, “It grows very well in our region.” The secret to the bur oak’s long life is its long taproot which anchors it deep in the ground, and its thick bark which resists fire. One of the most drought resistant of North American oaks, bur oak grows an impressive eighty to one hundred feet tall, and typically lives 200 to 300 years. With deeply lobed leaves and large acorns bearing characteristically fringed “hats,” bur oaks are readily distinguished from other oaks. “They are inspiring,” Kim says.
Despite its southern sounding name, the Kentucky coffeetree is an “iconic native tree,” according to Kim. Like bur oak, Kentucky coffeetree is quite drought resistant and can survive such urban conditions as compacted soil. In its youth, the tree is sometimes thought to be a bit gawky looking, with angular branches and tufts of foliage that start leafing out late in the season. Kim describes the foliage as refined. “As it matures, I think it is very appealing,” Kim says, noting that Kentucky coffeetrees can live to be 100 years old.
The female tree produces pods whose seeds were used as coffee substitutes – hence the name. The pods are persistent, typically remaining to add winter interest. Kim also recommends some male cultivars without pods, for those who want to avoid spring cleanup of the seeds. Although somewhat hard to find in garden centers, ‘Espresso’ and Prairie Titan® Kentucky coffeetrees are upright and narrow, especially good for small landscapes.
Shagbark hickory, another of Kim’s favorites, has distinctive, shaggy, exfoliating bark as it matures (about ten to fifteen years old). With a 200 year average lifespan, shagbark hickory’s 100-foot tall trunk will provide shade, edible nuts, and golden-yellow foliage in autumn. In spring, its large buds are striking as they unfurl from loose fitting scales.
Another tall tree, at 50-70 feet, the American beech, offers shiny green leaves and a bonus of edible nuts. Although it is not as resilient in very urban conditions, the oval-pyramidal American beech tolerates a variety of soils. “It maintains its clean and beautiful shape,” says Kim. “Its foliage stays neat.” For formal landscapes the beech is a natural.
Glad You Asked
Q. What is a good small native tree?
A. Persimmon typically reaches 40-60 feet. Kunso Kim values persimmon for its fruit, shape and bark. “Its bark is very elegant – a rough dark, brown,” he says. Persimmon fruit is best eaten when it becomes less bitter after the first frost. For free advice on other tree choices, visit www.mortonarb.org or call Plant Clinic at 630/719-2424.
Q. What is the difference between the native white oak and swamp white oak?
A. Both trees are native to Illinois. White oak one of our region’s largest trees at 60-100 feet, has deeply lobed leaves that may remain on the tree during winter. The brown leaves make a pleasant rustling sound in winter wind, and are effective alternatives to evergreens for winter privacy. Swamp oak is smaller, with heights ranging from 50-80 feet. Its distinctive leaves are two-toned with green on top and a silvery underside. Swamp oak, as its name implies, tolerates soggier soils although white oak can adapt to a wide range of soils, except for very alkaline soil.
At The Arboretum
See rare artifacts such as a buckeye specimen from a seed that George Washington collected in 1784, and watch horticulturists’ demonstrations, in the Arboretum “Open House,” Sunday, June 29, from noon – 4 p.m. Reserve tickets, $10-$15, at 800/650-5511.