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Noble Trees

You can probably think of some noble trees

By Martha Swiss ©2012
Penn State Master Gardener


At one time, forests covered much of Western Pennsylvania—acres of towering oaks, hickories, and beeches in dry upland forests, and sycamores, maples, and hemlocks in moist woods. Development in the 19th and 20th centuries destroyed many acres of original Pennsylvania forests.  Today, Pittsburgh has less overall tree canopy than many other cities.  Tree Pittsburgh and TreeVitalize, are working to preserve and expand the city’s green canopy, which includes many noble trees.

What is a noble tree?  A noble tree is the large sycamore you walk under on a hot summer day, casting welcome shade, or the massive oak you notice in winter for its magnificent silhouette of bare branches, or an old maple from your childhood that held a tire swing. In short, noble trees are those planted to endure for generations, large enough to cast shade and become fixtures in our landscapes and our memories.

California Redwoods
The most noble trees of all

Noble trees serve a critical role in our ecosystem.  They remove large amounts of carbon dioxide (about 48 pounds per mature tree in a year) and pollutants from the air. One mature tree creates enough oxygen to support two people for a year. Their roots absorb storm water runoff. They can reduce the “heat island” effect of pavement and buildings in urban areas. A well-tended canopy of large shade trees increases property values and brings higher revenues to shopping districts that are graced by tree-lined streets.

 


Tree growth rings
Tree rings provide a timeline

And it’s not just humans who benefit from noble trees. They provide shelter and nesting sites for countless birds, insects, and animals. Early spring flowers of many noble trees are an important nectar source for winter-starved pollinators. In the fall, nuts such as oak acorns and beech and hickory nuts provide critical winter food for turkeys, deer, bears, squirrels, chipmunks, and many other birds and mammals.

White oak branches
Massive branches of a White Oak

Because of their ability to grow to a massive size—80 to 100 feet or more tall and wide—noble trees should be planted with care and they do come with some tradeoffs. They can shed pollen in the spring, leaves and nuts in the fall, and twigs and branches throughout the year. In short, they can be messy. A mature shade tree can use a few hundred gallons of water in a day, making the soil beneath the dripline of a tree dry. Depending on the species of noble tree, it can be nearly impossible to grow grass and gardens beneath them due to the dense shade, fibrous roots, and dry soil. Poorly sited noble trees can become a hazard to power lines; they can heave sidewalks, infiltrate water and sewer lines, and endanger building foundations.

For these reasons, it is important to choose noble trees that are well suited to the particular conditions. They should also be sited carefully and maintained regularly by certified arborists. Healthy noble trees that are chosen and planted with care are treasures that can be enjoyed for generations.

Winter trees
Noble trees in winter

Before planting a noble tree, check the location of utilities like gas, water, sewer, electric, and cable lines to be sure they will not be adversely affected by the mature tree. Consider nearby sidewalks, driveways, and buildings—is there enough space for a large shade tree when it is mature? Be sure you know the location of your property line and don’t plant a large shade tree that will encroach on your neighbor’s property without his or her permission.

Tree trimming near utility lines
Noble trees and utility lines don't mix


If you are lucky enough to have space for a noble tree, consider any of the following deciduous trees (they lose their leaves in the fall):

Red maple (Acer rubrum)

Sugar maple (Acer saccharum)

American beech (Fagus grandifolia)

European beech (Fagus sylvatica)

Kentucky coffeetree (Gymnocladus dioicus)

Katsura tree (Cercidiphyllum japonicum)

Sweetgum (Liquidambar styraciflua)

Tulip tree (Liriodendron tulipifera)

Cucumbertree magnolia (Magnolia acuminata)

Dawn redwood (Metasequoia glyptostroboides)

Sycamore (Platanus occidentalis)

Sycamore trees
Distinctive Sycamore tree trunks

White oak (Quercus alba)

Scarlet oak (Quercus coccinea)

Pin oak (Quercus palustris)

English oak (Quercus robur)

Red oak (Quercus rubra)

American linden (Tilia americana)

Littleleaf linden (Tilia cordata)

American elm (Ulmus americana) (varieties resistant to Dutch elm disease include ‘Delaware #2,’ ‘Jefferson,’ ‘Liberty,’ ‘New Harmony,’ ‘Princeton,’ and ‘Valley Forge’)

In addition, here are a few suggested needled evergreen noble trees:

White fir (Abies concolor)

Eastern white pine (Pinus strobus)

Massive tree trunks
Massive Hemlocks & White Pines
in Cook Forest


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