Ten Trees to Plant More Of
For those who haven’t heard, the Emerald Ash Borer (EAB) has been found in Nebraska. More information on the insect can be found all over the internet (including http://nfs.unl.edu/nebraska-eab but suffice it to say that EAB has been heading our way for the last 10-15 years and it has now begun its devastation of Nebraska’s 40 million+ ash trees, including over a million planted in communities. It’s too early to say how quickly EAB will move across the state (it doesn’t move very fast unless hitching a ride with humans), but forestry experts expect it will kill most of the state’s ash trees in the coming years.
One strategy to help deal with the problem is to begin earnestly planting new trees that will be ready to take the place of our ash trees as they go away. It’s important to remember that species diversity is the key to a healthy and resilient community forest. Ideally no single species should make up more than 10% of a community’s tree canopy and yet many Nebraska towns are overstocked with just a few species, including green ash (Fraxinus pennsylvanica). To help whet the appetite, here are ten underutilized species that grow about the same size as ash and which deserve to be planted more.
|Bur Oak in North Platte, Nebraska|
1. Bur Oak (Quercus macrocarpa): As bold as the prairie-land it comes from, the bur oak is a wide-spreading tree that shrugs off the worst of our climate extremes including drought. The tree supports an incredible variety of wildlife and generally lives much longer than most trees when properly planted and cared for. One of the best things about bur oak is its shade-casting ability. Though only growing 50-60’ tall it can grow up to 100’ wide when room allows and shading an entire back yard.
2. Chinkapin Oak (Quercus muehlenbergii) is nearly as tough and adaptable as bur oak, but is a more upright tree growing 50-60’ tall and 40-50’ wide. This woefully underused tree is named for it unique chestnut-like leaves.
3. Elms (Ulmus spp). There are several new disease-resistant elms available that are easy to establish, fast growing and which cast good shade. Better types include Princeton American elm, Triumph elm, David elm and Frontier elm among others. Elms are pioneering species that generally won’t live as long as an oak, but our communities need such species as well. Size ranges from 50-80’ tall and 50-80’ wide depending on type.
|Pecan in Kearney, Nebraska|
4. Pecan (Carya illinoinensis) is one of the best trees for general landscape use, growing fast and tall and tolerating a wide range of soil conditions and weather extremes. Although it produces those delicious nuts, the pecan is generally not messy as the squirrels and birds clean them up about as fast as they mature. Ultimate size is 60-80’ tall and 40-50’ wide.
5. Bitternut Hickory (Carya cordiformis). Native to the oak woodlands of eastern Nebraska, the bitternut hickory has proven to be relatively tolerant of urban conditions. The tree is great for wildlife, turns a pleasing yellow in the fall and grows relatively fast to 50-60’ tall and 30-50’ wide.
|Bitternut Hickory fall color|
6. Sugar Maple (Acer saccharum). It seems that everyone wants a maple, especially the many red maple hybrids and cultivars such as ‘Autumn Blaze’ which are quickly becoming over planted. A good alternative is the sugar maple which is actually more acclimated to the Great Plains climate. There are many good cultivars available including the ‘Caddo’ variety from Oklahoma which shows amazing heat and drought tolerance. Sugar maples will grow 40-70’ tall and about as wide.
|Caddo Sugar Maple fall color|
7. Hackberry (Celtis occidentalis) is a tough-as-nails Great Plains native that is relatively common in communities throughout the region. It used to be planted in great abundance, but fell out of favor in recent decades and thus is slowly disappearing from communities. Although we shouldn’t plant them at the pace we used to, we should always be planting a few of them. Hackberry grows 50-70’ tall and 50-60’ wide.
8. Black Cherry (Prunus serotina) is native to eastern Nebraska woodlands but is almost never used as a landscape tree. That’s too bad as this tree has a lot to offer including nice spring flowers, good fall color, feeds a variety of birds and other wildlife, is relatively drought tolerant and is fast growing when young. The tree grows bigger than most cherries reaching 40-50’ tall and 25-40’ wide.
9. Meyer Spruce (Picea meyeri) is very similar in color and form to the Colorado spruce (Picea pungens) but is considered to be more tolerant of high-humidity and warmer nights, which could be a good advantage for this tree as our climate shifts to a generally warmer pattern.
10. Swiss Stone Pine (Pinus cembra) is a five-needle pine native to the Alps of Europe where its large seeds have long been consumed as food. The pine is somewhat reminiscent of the eastern white pine (Pinus strobus) commonly found in our area, though not growing nearly as large (typically 30-40’ tall and 20-30’ wide).
There are dozens of species, hybrids and cultivars of trees that have proven adaptable to our region so there is no reason our community forests can’t become much more diverse. A good place to learn more about these species is via the Nebraska Statewide Arboretum, either by visiting an affiliate site or by exploring several tree lists available on line at www.plantnebraska.org.
Justin Evertson, Green Infrastructure Coordinator
Justin Evertson, Green Infrastructure Coordinator