Native Trees with Smooth Bark

Smooth-barked trees for your landscape

Pawpaw (Asimina triloba). Photo by Kurt Stueber

A landscape with a variety of tree barks has visual interest, especially in winter. Trees have many variations in their bark -- color, texture, thickness, etc. When the trees are leafless, the bark becomes a very noticeable feature. This article focuses on trees with very smooth bark.

Unfortunately, trees with smooth bark are appealing to vandals. I've seen beech trees sadly defaced by obscenities, carved with a knife into the smooth bark on the tree trunks. If you're looking for a tree to plant beside the street or road, a smooth-barked tree may not be the best choice.

Many trees have smooth bark as young saplings, but only a few trees retain smooth bark for their entire lives. Here is a list of five native trees with smooth bark, even in maturity:

• American beech -- Fagus grandifolia -- Bark image

• Common witchhazel -- Hamamelis virginiana  -- Bark image

• American hornbeam -- Carpinus caroliniana -- Bark image

• Pawpaw -- Asimina triloba -- Bark image

• Yellowwood  -- Cladrastis kentukea -- Bark image

Also worth knowing

• Poison-sumac -- Toxicodendron vernix -- Bark image

Poison-sumac, a small tree (or shrub), is mentioned here only because it might be useful to know that it has smooth bark for identification purposes. Try not to touch poison sumac at all because twigs, leaves, bark, flowers, fruit, and even the roots contain urushiol. Urushiol is a natural oil that produces a itchy and potentially serious skin rash in most humans. This same oil is found in poison ivy and poison oak.

American beech in winter

An easy tree to identify

• Q. Which tree trunk in this photograph is an American beech?
• A. The American beech is the second large trunk from the right.

American beech (Fagus grandifolia) can be easily identified, even at a distance and even in winter, by its very smooth, silvery-gray bark. A strong second hint is the bleached-out, dead leaves still clinging on the tree in January.

Beeches grow throughout most of the eastern United States. Where you see one beech tree, you will often see several. The American beech is the only member of the beech family known to reproduce through root suckers. Root suckering of beeches is more common in the northern part of its range, where thickets of beech or many saplings clustered around a larger trunk may be seen.

Beechnuts are a valuable wildlife food. In American Wildlife and Plants, authors Martin, Zim, and Nelson list 17 species of waterfowl, game birds, and song birds that eat beechnuts. Animals that have been observed eating the nuts include black bears, deer, beavers, red and gray foxes, porcupines, squirrels, chipmunks, mice, and of course, squirrels. Deer also browse the leaves and twigs.

Along the rural backroad of Todd County, Kentucky, where I photographed this beech, half a dozen beech trees grow within a hundred yard radius of this tree. This group of beeches grows on a northwest-facing, steep, fairly moist hillside above a small, narrow valley ("holler") where a creek flows.  I think the location could be described as a "messic ravine." 

In maturity, the American beech is a tall, broad tree -- up to 100 feet in height and 75 feet in width. Beeches are slow-growing trees that usually live 200-300 years, and they are strong-limbed trees that resist weather damage. The beech in the photo is probably several decades older than I am!

Ten Native Trees with Leathery Leaves

Trees with tough, durable foliage

Leathery leaves of Quercus stellata (post oak)

Image courtesy of Iowa State Extension Service

In tree books and nursery catalogs, the term "leathery leaves" is sometimes used. What does "leathery" mean?

Leathery is an adjective that is used to describe a leaf's texture -- that is, how it feels when you hold the leaf between your fingers. A leaf's texture is a entirely separate characteristic from its size, shape, or color.

"Leathery" is the opposite of delicate. Leathery leaves are tough and durable. They are a bit thicker than most leaves, and they're somewhat pliable. They have a texture that's similar to thin leather. They are not easily torn by accident. A leathery leaf would never be called "limp" -- rather, they are substantial leaves.

When you're wondering if a tree's foliage would be described as leathery, examine a mature leaf. The leaves of a few tree species are leathery as soon as they pop out of the bud, but the leaves of various others are delicate at first but become leathery as they mature.

Homeowners should be aware that leathery leaves are slow to deteriorate. Raking will be needed to remove fallen leaves from the lawn.

Here are some examples of deciduous native trees of North America that have leathery leaves. The Latin names are linked to the trees' respective pages in the USDA Plants database.

Alnus serrulata -- Hazel alder (leaf image)
Fagus grandifolia -- American beech (leaf image)
Liquidambar styraciflua -- American sweetgum (leaf image)
Magnolia acuminata -- Cucumbertree magnolia (leaf inage)
Prunus serotina -- Black cherry (leaf image)
Quercus alba -- White oak (leaf image)
Quercus bicolor -- Swamp white oak (leaf image)
Quercus prinus -- Chestnut oak (leaf image)
Quercus stellata -- Post oak (leaf image)
Rhododendron maximum -- Rosebay rhododendron (leaf image)

Nine native trees that hold leaves in winter

Native broadleaf trees with persistent foliage

Have you noticed that a few broadleaf trees change color in fall, but don't drop their leaves? Many of their brown leaves cling to the tree throughout winter and early spring until new leaf growth begins. This characteristic is called marescence.

Here are nine native trees that behave in this fashion.

• American beech (Fagus grandifolia)
• American hophornbean (Ostrya virginiana) also called ironwood
• Sycamore (Platanus occidentalis) also called American planetree or buttonwood
• Black oak (Quercus velutina)
• Blackjack oak (Quercus marilandica)
• Northern pin oak (Quercus ellipsoidalis)
• Pin oak (Quercus palustris)
• Shingle oak (Quercus imbricaria)
• White oak (Quercus alba)

Perhaps it's no surprise to you that the majority are oaks. Owners of these oak trees often complain that they shed leaves all winter long. I know an elderly lady who is very opposed to oaks as the national tree. She has lived her entire adult life under big white oaks, and she hates the way they drop their leaves a little at a time, all winter. "Just not tidy trees," she told me.

Trees with some winter foliage will perform better as a windbreak, screen, or sound barrier than trees that have dropped all their leaves.

They will also cast more shade in the winter than trees that have dropped their leaves. Sunshine on the house in winter is generally a good thing, so consider that when choosing a planting site for a tree that keeps winter leaves.

Our pin oak on the evening of February 21.

Look at all those leaves!

Image credit: Pin oak leaf drawing by J. R. Stacy of the U.S. Geological Survey.

Tiny insect is big problem for Louisville Slugger

Ash baseball bats threatened by emerald ash borer

The Louisville Slugger is a baseball bat that has been manufactured in Louisville, KY, since 1884. Though also available in aluminum and maple, the traditional Louisville Slugger is made of white ash -- and not just any white ash.

The process of making a Louisville Slugger begins with selecting the timber itself. Although maple is rapidly gaining in popularity among today’s pros, the majority of bats are made from white ash. However, not just any white ash can become a Louisville Slugger. In fact, the only ash up to Louisville Slugger standards grows along a 200-mile stretch of land on the New York-Pennsylvania border. The soil, rain, sun – everything is just right there. That’s where the best bats in the world, Louisville Slugger bats, come from.

Source: Slugger Magazine

As you might imagine, the Louisville Slugger Company is concerned about the emerald ash borer, an Asian insect that has been wreaking havoc among North America ash trees. The emerald ash borer has spread through parts of Canada, Pennsylvania, Ohio, West Virginia, Maryland, llinois, Michigan, and Indiana. As of yet, the insect has not reached the area where the ash timber for Louisville Sluggers is produced.

Emerald ash borer tunnels under an ash tree's bark. Photo by National Park Service

The Louisville Slugger company is bracing itself for the possibility that the emerald ash borer will reach and destroy the ash forests that produce Slugger lumber. Company labs are conducting research on other woods for bats, especially beech.

In a press release about the Emerald Ash, the Louisville Slugger company urges the public to avoid transporting firewood. When firewood is moved out of the area where it was cut, the emerald ash borer may ride along, expanding its range far more rapidly than the insect could do without human assistance.

Only time can tell what will happen to America's ash trees. We certainly hope for a solution to the emerald ash borer problem, but you might want to buy an ash Louisville Slugger bat (link opens a PDF) while you still can.

Technorati tags: Louisville Slugger, emerald ash borer, white ash

Tall trees that resist wind and ice damage

23 tall-growing native trees that resist wind and ice damage

Updated, 3/6/10.

All of these trees can reach 75-100 feet in height or more when mature. All are native trees of North America with moderate to good resistance to damage by wind and ice.

Trees marked with an asterisk below should be considered moderately resistant. A general rule to remember is that strong evergreens are not as resistant to wind and ice damage as strong deciduous trees. Because of their foliage, they tend to catch more winter wind, snow, and ice. (That's why evergreen trees are often planted in windbreaks.)

1. Acer nigrum -- Black maple
2. Acer saccharum -- Sugar maple*
3. Carya cordiformis -- Bitternut hickory
4. Carya glabra -- Pignut hickory
5. Carya illinoensis -- Pecan
6. Carya ovata -- Shagbark hickory
7. Carya tomentosa -- Mockernut hickory
8. Fagus grandifolia -- American beech
9. Gymnocladus dioicus -- Kentucky coffeetree
10. Juglans nigra -- Eastern black walnut
11. Liquidambar styraciflua -- American Sweetgum
12. Magnolia acuminata -- Cucumbertree magnolia
13. Picea pungens -- Colorado spruce
14. Pinus ponderosa -- Ponderosa pine*
15. Pinus resinosa -- Red pine*
16. Platanus occidentalis -- Sycamore, American planetree*
17. Quercus alba -- White oak
18. Quercus bicolor -- Swamp white oak
19. Quercus borealis -- Northern red oak
20. Quercus macrocarpa -- Bur oak*
21. Quercus velutina -- Black oak
22. Taxodium distichum -- Common baldcypress
23. Tsuga canadensis -- Canada hemlock*

Remember -- if the weather is bad enough, any tree can lose branches, snap its trunk, or even lose its grip and fall over. You should use good judgment about keeping your home safe. It's not wise to have big trees next to your house, no matter what kind of trees they are. 

For a (usually) safe distance between house and tree, allow half of the mature tree's spread (half of the diameter of its crown). If the mature tree will have a spread of 70 feet, it should be planted at least 35 feet from any buildings. This does mean that many suburban properties are too small for large trees.

If you want a guarantee that you will never have to cope with fallen branches or storm-damaged trees, simply remove all trees from your property. That should eliminate the problem.

Sources for the above list include:

Native Trees, Shrubs, and Vines for Urban and Rural America: A Planting Design Manual for Environmental Designers by Gary L. Hightshoe, published in 1988 by Van Nostrand Reinhold, New York.

Ice Storm Damage to Urban Trees, an article in the appendix of Storms Over the Urban Forest, a publication of the USDA Forest Service. (This article's table, "Ice storm susceptibility of tree species commonly planted in urban areas" is reprinted in many reputable articles about ice damage susceptibility on the internet.)

Trees For Nebraska Ice Storm Recovery and Susceptibility of Trees to Ice Storm Damage in the Great Plains, published by the Nebraska Statewide Arboreum

American beech seen at Fort Donelson, TN

A few notes about Fagus grandifolia

These beech trees grow at Fort Donelson National Battlefield at Dover, Tennessee, on a bluff overlooking the Cumberland River. They grow near each other, so it's likely that they are clones of each other. Beech trees send up suckers, and those suckers become beech trees that are genetically identical.

Beech trees are easily identified by their smooth, gray bark. Often the bark is not uniformly colored; it may have a splotchy gray appearance.

In a national battlefield, it is a federal crime to deface government property, but these trees have suffered a good bit of carving on their trunks.

Beech nuts are a valuable food for wildlife. The small, three-sided nut is borne in a prickly husk that splits open when the nut is ripe. The nut is enjoyed by a wide variety of birds and mammals, as well as man.

Beech trees prefer a mildly to moderately acidic soil and a fairly moist site with good drainage. They are not particularly susceptible to disease or weather damage, but they can be injured by drought, compacted soil, and chemicals that wash off streets. Young trees can be damaged by sunscald (long hours of intense sunshine.) They prefer -- and need! -- a shaded location.

Beech trees are slow-growing, but long-lived. They may live up to 300 years. I speculate that the trees in the photo are about 145 years old. It is likely that these bluffs were cleared of trees when the Confederate forces built fortifications here in 1861-62. These trees probably sprang up from roots in the ground after the site was abandoned by Union forces in 1863.

Comparison of the fuel value of firewoods

Wood burners agree that oak and hickory are great firewoods.

If you have a wood stove or fireplace, it's prudent to know what types of wood will produce the most heat per cord (or rick, or truck-load, or whatever unit by which you buy wood!)

A great chart is available at Firewood Ratings and Info. A short study of the chart reveals that oaks, hickory, white ash, and beech wood are some of the very best.

The Utah State Forestry also has an excellent firewood ratings chart with information about a somewhat different set of trees than would be found in my area (Kentucky). It gives high ratings to osage orange, pinon, honeylocust, and black locust, as well as oak and beech.

Compare those results with the following observations from about 130 years ago. It's interesting, but not surprising, that they liked oak, hickory, and white ash as firewoods. Beech didn't make their list, for some reason.

It is a great convenience to know the comparative value of different kinds of wood for fuel. Shellbark hickory is regarded as the highest standard of our forest trees, and calling that 100, other woods will compare with it for real value as fuel for house purposes as follows :

Shellbark Hickory, 100
Pignut Hickory, 95
White Oak, 84
White Ash, 77
Dogwood, 75
Scrub Oak, 73
White Hazel, 72
Apple Wood, 70
Red Oak, 67
White Beech, 65
Black Birch, 62
Yellow Oak, 60
Hard Maple, 59
White Elm, 58
Red Cedar, 56
Wild Cherry, 55
Yellow Pine, 54
Chestnut, 52
Yellow Poplar, 51
Butternut and White Birch, 43
White Pine, 30.

It is worth bearing in mind that in woods of the same species there is a great difference, according to the soil on which they grow. A tree that grows on a wet, low, rich ground will be less solid and, less durable for fuel, and therefore of less value than a tree of the same kind that grows on a dry and poor soil. To the ordinary purchaser oak is oak and pine is pine, but for home use, the tree grown on dry upland and standing apart from others, is worth a great deal more.

Source: Manufacturer and Builder, January 1878. Volume 10, Issue 1, page 19.