A publication of the Nebraska Statewide Arboretum The Seed Spring 2007 Plains-proven plants to know and grow The Value of Large Trees Justin Evertson are just some of the ways we relate directly to trees. These physical and Not that long ago most Nebraska mental comforts are so uplifting that communities were full of large American many people develop a very strong elms. Their tall, arching habit, fast spiritual connection to trees. What else growth and adaptability to a wide range explains people who have climbed or of soil conditions made them a popular chained themselves to important trees to choice for planting in towns from prevent their destruction? Falls City to Chadron and all points in between. Because of its wide-spreading The Big Tree Disconnect habit, American elm was especially Because we now know how truly popular for planting along streets. Often valuable large-growing trees are, people the canopies of individual trees met over and communities must be doing all they the middle of the street, creating a ceiling can to properly plant and care for them. of green that would sometimes stretch for Right? Wrong!! In fact, according blocks at a time. Unfortunately Dutch to research by the Nebraska Forest elm disease raced across the state in the Service, the amount of tree canopy cover 1960s and 70s and, in what now seems provided by large trees in most Nebraska like the blink of an eye, the elms were communities has declined significantly gone. And they have been sorely missed. since the days of the American elm. Although the benefits weren’t When the elms died, many were never completely understood at the time, replaced. And where replanting did those who planted the elms knew large occur, smaller-growing trees—selected Large trees frame roads in Nebraska City’s trees were important to a community. primarily for spring flowers or fall Steinhart Park. Today, thanks to research from across color—were often the choice for the country, we can now quantify planting. This trend toward smaller trees community’s tree resource. Having a Inside economically many of the benefits has now been broadly referred to as the wider variety of species greatly reduces the risk of a massive die-off of trees that large trees provide. For example, “dwarfing of the community forest.” The Truth about Roots properly placed and well-cared for Another disturbing problem facing when the next disease or insect comes trees can increase property values by community forests is the lack of species along. Incredibly, the Dutch elm disease 10 percent or more while reducing diversity. If any lesson should have lesson was somehow forgotten and once An Ode to Hackberry energy costs by up to 15 percent. Other been learned in the wake of Dutch elm again a single species of shade tree, this measurable benefits from trees include disease, it is that a broader diversity of time green ash, has come to dominate Pine Wilt Disease and cleaner air, reduced atmospheric CO2, tree species is vital to the health of a The Value of Large Trees continued on page 5 Emerald Ash Borer better-managed stormwater, extended life of streets, more attractive communities and better human health and well-being. Trees with a Split When added together, the benefits of Personality large-stature trees can exceed $65/tree/ A Few Big Trees for the Future year*. Bob Henrickson The Simple Act of Of course people also benefit directly from trees through the mental One of the benefits of working Planting Better Trees and physical comforts they provide. for the Nebraska Statewide Arboretum The coolness of the shade on a hot (NSA) is the opportunity to visit its Return of the Elm summer day; the sounds of rustling network of arboretum sites, parks, historic properties and other public leaves and singing birds; a squirrel flying Ten Elms to Try effortlessly through the branches; the landscapes that spans the entire state. wondrous fragrance of linden blossoms Most of the landscapes that make up the in late spring; the colorful change of Arboretum are not extensive landscapes Fifty Large-growing leaves in autumn; and the magic of but local arboretums and parks where Trees for Nebraska frosted branches on a winter morning… an impressive variety of trees has been assembled. I have visited most of the Arboretum sites over the years and I Tree-planting for Success arboretum.unl.edu Phone: 402-472-2971 Lincoln, NE 68583-0715 University of Nebraska Box 830715 P.O. Arboretum Nebraska Statewide learn something new every time. By definition an arboretum is a place where trees for grown for the purpose of education, and what better place to become familiar with new tree selections or alternatives than a local arboretum? Forest Lawn Cemetery in Omaha is home to many People want to plant trees they are stately trees, including this large tuliptree. familiar with and have seen in the landscape. They also want to be assured that they will grow under regional conditions. A local arboretum is the Tuliptree perfect place to observe and learn about Liriodendron tulipifera plants they might not be familiar with. Native to the eastern half of the U.S., Below is a list of some of the the tuliptree is a stately tree for large wonderful trees I’ve observed or grown. spaces. The leaves are waxy and smooth, Generally they remain confined to retaining a clean appearance through the U.S. Postage PAID arboretums and parks, but in my opinion summer and turning bright yellow in fall. Nonprofit Org. they have a lot of potential and have The flowers are the size and shape of Nebraska Lincoln, NE Permit 46 proven they should be planted more. garden tulips, blooming in May after the Statewide These trees have stood the test of time. first leaves have expanded. The beautiful It’s time to get them out of the arboretum two-toned orange-yellow petals are often rboretum and into our home landscapes. A Few Big Trees continued on page 2 arboretum.unl.edu A Few Big Trees continued from cover Turkish Filbert hidden by the foliage and are best viewed Corylus colurna from a two-story window. There are This uncommon tree is handsome, beautiful trees growing on the campuses sturdy and trouble-free. The deep green, at the University of Nebraska in Lincoln toothed foliage remains clean throughout (UNL) and at Midland Lutheran College the summer and seems to be free of in Fremont. The Nebraska champion is insect and disease problems. The gray- located in Oakland, a big, impressive tree brown bark is heavily textured and the with a 4’ diameter trunk. Another large branches develop a very attractive formal specimen is located in a church courtyard outline. In early spring the clusters of in Humphrey, Nebraska. This tree has long male catkins dangle from the bare performed well in the eastern half of the branches like tarantula spiders. Though state and deserves to be planted more. native to Europe and Asia, it seems to thrive in Nebraska and a number Amur corktree of outstanding specimens can be seen Phellodendron amurense at UNL and at the Nebraska Game and Parks Commission headquarters This handsome medium-sized in Lincoln. Out west, a young tree is tree has deep green, shiny leaves that thriving in Lexington at the Dawson remain clean all summer. The bark County fairgrounds, but the best on old trunks is ridged and furrowed, specimen in the state is a 50’ beauty at forming a beautiful cork-like pattern. the Glen Viehmeyer Arboretum in North One of the best features of this tree is the Platte. This tree is underused and can be broad-spreading habit, open crown and difficult to locate in commerce, but it’s horizontal branch arrangements. This worth the hunt! tree is native to the Amur River region in China, the same area as Amur maple and Amur chokecherry. Beautiful specimens Bitternut Hickory of corktree are growing at UNL, Peru Carya cordiformis State College, Steyer Park in Blair and This relatively fast-growing, Memorial Park in Tekamah. An Amur beautiful tree is native to southeast corktree has been performing well in the Nebraska along the Missouri bluffs and Kimball arboretum in western Nebraska along creeks and rivers as far west as for over 12 years. The male selections Wahoo and Beatrice. In rich, woodland ‘Macho’ and ‘His Majesty’ are fruitless sites the bitternuts typically develop and noted for their thick, leathery leaves several primary vertical limbs, forming and spreading growth habit. an arching shape. Their tight, relatively smooth bark and bright yellow fall color Overcup Oak are reason enough to plant this tree. In Quercus lyrata spring, the long male catkins “hang like tinsel from the branches and are visible Overcup oak is the southern below the leaves” (Guy Sternberg, Native counterpart to swamp white oak, native Trees for North American Landscapes). from the southeastern U.S. west to Hickories develop long taproots and Missouri and Oklahoma. This is one of can be difficult to transplant, however the most flood-tolerant oaks and it grows with today’s air-pruning pots and root- naturally on poorly-drained, heavy clay restricting fabrics, the root systems soils. The acorn is almost fully enclosed produce a branching root system. Our by the cup and falls from the tree intact. native seed source should yield a more The cups provide flotation and help adaptable tree for areas throughout to disperse the seeds under flooded eastern Nebraska. conditions. The dark green, leathery The state champion at Wyuka leaves turn dull gold in fall.