Do you have a spot in your yard or garden for a tree? Consider planting an oak. Oak trees were named America’s National Tree in 2004, and the White Oak is the designated Illinois State Tree. Of the hundreds of oak species, about 20 are native to Illinois.
Hardwoods known for their sturdiness and longevity, oaks can live for more than 200 years. The longest-lived native oak, the white oak, has an average lifespan of 300 years and can, under excellent growing conditions, live up to 600 years.
Depending on type, the trees may be small and shrubby or enormous and spreading. None are too fussy about soil and can adapt to most conditions, though they prefer a sunny site. There are two main families of oaks: white (native northern Illinois examples include bur oak, swamp oak, chinkapin oak) and red (such as northern red oak, blackjack oak, pin oak). The trees can be identified by the shapes of their leaves.
Oaks grace the human landscape with beauty, shade, and fall color. And for the wildlife community, they stand tall. Oaks support 534 species of butterflies and moths, more than any other native tree. Caterpillars of these species develop on oak leaves and, like all caterpillars, are a crucial a protein source for birds, particularly during breeding season. While oak leaves stock the nursery pantry for such a large number of butterflies and moths, all parts of the oak—the leaves, branches, bark, and roots—provide habitat, including nesting materials and sites, roosts for birds, and concealment and shelter for mammals, amphibians, reptiles, and insects.
The oak tree is an important part of nature’s food chain. About 100 U.S. animal species eat acorns, the fruit of the oak, which fortuitously ripen about the time—August to December—when other native food sources are beginning to diminish. Acorns support the seasonal diet of many species of birds, from raptors to songbirds, and of mammals great and small. These “nuts” were an important feature of the Native American diet. William Bryant Logan, in his prodigiously researched book, Oak: The Frame of Civilization, claims that over the millennia, humans have followed oaks to new territories, knowing that where there are oaks, there will be food. Even today, you can find acorn recipes online. So many critters feed on acorns that a blogger for the National Wildlife Federation called them “the cheeseburger of the forest ecosystem—fairly easy to find and neatly packaged.” And of course, you can grow your very own oak tree from an acorn, although it will take a while before it produces acorns of its own.
Oaks are prized for their hardwood, long used for furniture, flooring, and shipbuilding, among others. White oak is the preferred material for the staves of whiskey barrels. King Arthur’s roundtable is said to have been made from a single cross-section of an oak tree. The bark of the oak tree has been used to make a tea for ailments such as diarrhea, cough, cold, fever, bronchitis, appetite stimulation, and digestive aid, and extracts have been used as liniments or added to bath water for pain, swelling, and skin irritation, though some experts caution that no scientific evidence supports these remedies, and possible side effects are unknown. Magical properties are attributed to oak trees; for instance, dreaming of resting under an oak predicts long life and wealth, and dreams of a fallen oak presage the loss of love.
The character of some of the most beautiful natural preserves in the Chicago region is defined by old oaks; yet in many cases young oaks are not managing to replace these venerable trees. The oak tree has endowed so much aesthetic and practical value to humankind, and it has occupied such a towering place in human myth and imagination. How could we not want to preserve and protect this companion to human development? If you’re thinking of planting a tree, consider the oak!
Artwork by Iggy Oblomov
William Bryant Logan, Oak: The Frame of Civilization, 2005, W. W. Norton & Compan
Oak Tree Genus: Quercus
Blackjack Oak: Quercus marilandica
Bur Oak: Quercus macrocarpa
Chinkapin Oak: Quercus muehlenbergii
Northern Red Oak: Quercus rubra
Pin Oak: Quercus palustris
Swamp Oak: Quercus bicolor
White Oak: Quercus alba
Butterfly, Moth Order: Lepidoptera