Landscaping with Native Trees
by Guy Sternberg

ARTICLE FIRST APPEARED: 1995 Fall

(Co-written with Jim Wilson)

According to a terrific new book entitled Landscaping with Native Trees -- co-authored by TWG subscriber Guy Sternberg and Jim Wilson -- there are nearly 100 oak tree species native to the United States, out of about 450 worldwide. Oaks grow naturally in all but one (Idaho) of the contiguous 48 states, and there are 20 species indigenous to Illinois. The diversity of oak species is greatest in southern Illinois, with fewer species to be found as you go northward. With the help of several renowned experts on oaks -- George Ware, retired dendrologist of The Morton Arboretum; Guy Sternberg, a staff member of the IL Dept. of Natural Resources and founding member of the Int'l. Oak Society, Connor Shaw, owner of Possibility Place Nursery, which grows oaks from acorns gathered locally, and John Schwegman of the IL Dept. of Natural Resources -- TWG presents, "Oaks for the Chicago Region".

Introduction

"Oaks are simply a fascinating genus of plant", says Guy Sternberg, " and you can find an oak for almost any landscape situtation. Unfortunately, oaks have received an undeserved reputation for being tricky to transplant and to propagate vegetatively, and so have not been as widely planted as they should. But all of those problems have been overcome and I think you're writing about the landscape tree of the 21st century. The oak is America's national emblem -- and for good cause."

Ask Alan Branhagen, deputy director of the Winnebago Co. Forest Preserve District, and he'll say, "Unfortunately our oak forests are not faring well. They are changing into a different forest dominated by maples and exotic shrubs. This is bad news economically because sugar maples provide lower value timber than either oak or hickory. It is also bad news ecologically because it diminishes the biological diversity of our region, reduces the #1 fruit (the acorn) consumed by wildlife, and diminshes the amount of foliage fed on by the insects favored for protein by Illinois' migratory bird population."

Listen to Dr. George Ware and he will tell you, "The oaks in the American landscape are very old and many are nearing the end of their useful lives -- especially because people abuse them so badly. Ever since the pioneers arrived, we've been building homes in the midst of oak groves, thus badly damaging their shallow root systems, and we've been removing the natural leaf mulch which feeds them acid and we've been installing lawns which eventually poison them with alkalinity. We have paid very little attention to the oak in ornamental planting, possibly because the tree lover has wrongly assumed that oaks grow slowly. A complete fallacy! I hope that people begin to re-oak America, and learn the oaks' ecological lesson -- that one who lives with oak trees should try to work with them on their own terms, or, stated another way, create or re-create the woodland soil conditions associated with them."

In presenting discussion of the attitributes of the oaks most suitable for Chicago area landscapes, TWG adds several caveats. First, space prevents discussion of every last IIlinois' oak species, so we have limited the list to those which are both native to Illinois and have the best landscape value. To make life a bit easier, our experts have done their best to rank these oaks in order of their ability to withstand the alkaline urban conditions we have created and their transplantability. Thus -- in our opinion -- the oak with the greatest adaptability to the typical conditions of the Chicago region is the:

Shumard Oak [Quercus shumardii]: According to Plants That Merit Attention, edited by TWG subscriber Janet Meakin Poor, the Shumard Oak "is a handsome tree that tolerates adverse sites. It makes a good street or park tree, with attractive, deep green, glossy foliage and a rounded, moderately dense crown. Its fall color is a distinct asset, and its tolerance of alkaline clay soil (pH range of 6.9-7.8) is valuable. Shumard Oak grows well where Pin Oak won't. It will tolerate wind, wet, dry, and stressful conditions. A Shumard Oak leaf is pictured on the front cover of Gray's Manual of Botany." Sources: Berthold (Elk Grove); Countryside (Crystal Lake).

Shingle Oak [Quercus imbricaria]: Shingle Oak is a very beautiful oak tree. Shingle Oaks make a great landscape tree and should be more widely available in the Midwest, because they tolerate calcareous (alkaline) soils. It is pyramidal in youth and matures to have a rounded top, attaining a height of 40-50 feet. They prefer moist, rich, well-drained acid soil but they tolerate drier soils and most city conditions. The Shingle Oak is found in nature with Hill's Oak, Hickory, and Buckeye, and in low areas with Swamp White Oak and River Birch. It is unusual among oaks in that its leaves are neither lobed nor toothed but have an entire margin and resemble the leaves of a magnolia (except that it has a sharp tip). Its shiny, dark green leaves turn yellow or reddish brown in the fall, and persist well into winter. It is easily grown from its buttonlike acorns, which mature every other year. Its name is derived from the wood's usefulness as shingling material, and was used as such by the French colonists at Kaskaskia, IL. Sources: Bald Eagle (Fulton); Lafayette Home (Lafayette); Possibility Place (Monee); Arthur Weiler (Zion);.

Northern Red Oak [Quercus rubra or Q. borealis]: Northern Red Oak is the only oak in the Maple-Linden community. No other oak can germinate and grow in so much shade, and this is also the most cold-tolerant of the eastern oaks. It is an attractive tree with large, glossy leaves, which unfurl in spring as deep red and become maroon red to brown in the autumn. Its leaf form can vary a great deal even on the same tree so only its acorn can be relied on for identification. It grows moderately fast, developing a straight trunk with branches that usually extend upward. This tree transplants well, but it is easily damaged by drought when young and does not compete well with grass as do most other shade trees. It requires ample space for the horizontal spreading of its roots and crown, which can reach 75 feet. It is easily grown from acorns will germinate in spring. Being so hardy, it can endure for 200-300 years and is a valuable timber tree because of its northerly range and tall heights. Sources: Alsip (Alsip); Amling's; Bald Eagle; Berthold's; J. Carlson (Rockford); Clavey's (Woodstock); Countryside; Fertile Delta (Chicago); Charles Fiore (Prairie View); Four Seasons (Chesterton, IN); The Growing Place (Naperville); Hinsdale Nursery (Hinsdale); Johnson's (Menomonee Falls, WI); LaPorte County (LaPorte, IN); Lied's (Sussex, WI); Possibility Place; Prestige (Bartlett); Arthur Weiler.

Bur Oak [Quercus macrocarpa]: The coarsely-branched but graceful Bur Oak is a bold and impressive element of northern IL landscapes. This is the oak that challenged the prairie grass for survival, because its thick furrowed bark resists even prairie fires and leads the way for the forest to succeed the grassland. In pre-settlement times it was found in open groves in the prairie, and huge specimens -- 300 years or more in age and reaching 80 high and 100 feet wide -- may still be found, especially in open woodlands. It is a highly adaptable tree, even tolerant of dry or wet clay conditions. Its leaves are thick and glossly green with a silver undercoat, so that the tree glimmers from a distance. Young Bur Oak saplings grow rather slowly, but growth accelerates after five or six years, producing an impressive young tree by the tenth year. The slow start should not deter people from planting Bur Oak as it is a greatly valued landscape tree when mature. Bur Oak can be transplanted as a young sapling if care is taken, but it becomes more difficult with trees more than 6-8 feet tall. Mulching the young trees and protecting them with stakes is recommended. The Bur Oak's wood is much harder than that of a White Oak. Suggested neighbors included other Oaks, Hickories, Hackberry, Hawthorn and Crabapple. Sources: Amling's; Berthold; Charles Fiore; Johnson's; J. Carlson; Lafayette Home; LaPorte County; Lied's; Possibility Place; Spring Bluff (Sugar Grove); Arthur Weiler.

Black Oak [Quercus velutina]: This tree is often called the "Yellow Bark Oak", because its inner bark was historically used as the best source of yellow or ochre-colored dye (hence its earlier name, Q. tinctoria). This is a tree which grows sufficiently fast to be well used in the home landscape, and it is rugged enough to stand up to dry, gravelly soils . It will grow to 80', with a straight, deeply grooved trunk, and glossy dark green leaves which turn golden brown in fall. It yields acorns every other year. Sources: Bald Eagle; Lafayette Home.

Chestnut Oak [Quercus prinus]: The Chestnut Oak is a handsome tree which reaches about 40-60' in height. It has a straight, dark, central trunk with a conical to rounded crown. Its glossy, wavy-edged leaves have long yellow petioles that create a special foliage effect. This oak grows moderately fast once established. Young trees are not difficult to transplant and fare well in the Illinois landscape. It is easily grown from acorns, and it was once called the Basket Oak since the wood easily splits into splints. I've read its leaves are also beloved of cows, so it was once called the Cow Oak. Sources: Berthold; Lafayette Home.

Chinquapin Oak [Quercus muehlenbergii]: Chinquapin Oak is native to uplands and dry slopes, thriving on highly alkaline soils typical of rocky limestone bluffs. It reaches its greatest size in rich bottomlands, however. Its glossy, large-toothed (or finely lobed) leaves are rather small in comparison to the leaves of most oaks. For many years, a Chinquapin's shape will be irregular and dominated by a white-barked, conspicious trunk, but as the tree ages it becomes more rounded. It usually grows about 50' tall, but occasionally grows over 100' tall. It grows moderately fast [Groe & Boon say slow], and does well on alkaline clay soils. It should be much more used in the landscape. Its name is derived from the Algonquin word chechinkamin, meaning "great berry" and referring to the chestnut tree. The leaves of this oak resemble those of the chestnut, and the acorns are sweet and edible and loved by wildlife. The tree can last 200 years, but is difficult to transplant. Good neighbors are other Oaks, Linden, Hackberry, Hophornbeam, and Hawthorn. Sources: Bald Eagle; Lafayette; Possibility Place.

Scarlet Oak [Quercus coccinea]: "Scarlet Oak may be the most beautiful of all oaks", write Bill Boon and Harlen Groe in Nature's Heartland, "Its fall color is the richest red of the autumn. [Some] call it the Ôglory tree'." Scarlet Oak looks very much like a Pin Oak or a Black Oak, but its acorns differ. It will grow about 2' per year, and is considered the fastest grower of the oaks. It matures to 70', with a narrow but open crown. Trees larger than seedlings are difficult to transplant, but its beauty is well worth the effort. Sources:

Swamp White Oak [Quercus bicolor]: Swamp White Oak is one of the most suitable native oaks for landscape use in northern Illinois. It prefers wet, acid soils and is most at home even in inhospitable clay soils, a desirable attribute for success as an urban tree, and certainly does fine in well-drained soils. Unfortunately, it will develop chlorosis when it gets inadequate iron characteristic of alkaline soils. Young saplings are not difficult to transplant. As a planted tree it usually reaches 60-70' in height, and lives to be about 125 years old. It grows rapidly, gaining 2' every year. When mature, trees may have a broad vase-like shape. The slightly lobed leaves are glossy green on the upper side and whitish on the lower (hence "bi-color"). It will turn bronze in the fall and keep its leaves all winter. This is the tree that is sold as "White Oak" for flooring and furniture. Good neighbors include River Birch, Ash, Maple, and Shingle Oak. Sources: Possibility Place Nursery

Hill's Oak or Northern Pin Oak [Quercus ellipsoidalis]: From Boon & Groe: "This tree has only been known to science since it was discovered (in northern Indiana?) by J.E. Hill in the 1920's. Indeed, of Illinois' oaks it alone is only found in our northern counties. Its appearance and leaf shape is very similar to the Pin Oak, but its acorn is quite different. Hill's Oak typically finds its home on drier and sandier soils typical of the savanna, but in McHenry County, for example, it even grows in wetlands. IDOT has even used this tree in expressway planting! The tree has a short trunk with many small branches and grows 50-70 feet high. The leaves are shiny green turning to yellow, brown or purple in the fall, and they frequently persist into the winter. It is a slow grower, long-lived, difficult to transplant, and intolerant of very high pH soils. Its hardiness makes it a very promising landscape tree. The acorns mature every other year. Good neighbors include: Sources: Possibility Place Nursery

White Oak [Quercus alba]: The State tree of Illinois, the White Oak is especially dependent on the forest environment. The shelter created by a nearly continuous canopy of forest trees, which favorably modulates the temperature and moisture in the atmosphere and soil, is necessary for this 100' tall oak. Removing the surrounding forest usually initiates decline and death for the White Oak which has been singled out to be saved in the landscape! White Oak transplants with difficulty and does not grow well in clay soils, especially those with spring wetness problems. It is probably best established by planting either acorns or very small saplings in well-drained soil and providing a mulch for many years. Sources:

Pin Oak [Quercus palustris]: Pin Oak is easily recognized from a distance by its straight trunk and many horizontal branches, the lowest of which may droop to the ground. The pointed-lobed leaves are usually a brilliant red in autumn, and may persist right into spring. The place of the Pin Oak in the native landscape is on poorly drained soils, where it may grow to heights of 60-80 feet or more. It grows rapidly after a year or two of establishment. Its shallow, compact root system makes it easy to transplant, and this is probably a reason it is the most frequently planted oak in the United States. However, in the Chicago region the yellowing of its leaves (chlorosis) is a serious problem. This condition is attributable to iron unavailability in the alkaline soils associated with our glacial landscapes. It is possible to correct chlorosis by applications of chelated iron, but the treatment must be repeated annually. Trying to solve the problem by modifying the soi to reduce alkalinity is very difficult. For these reasons the desirability of planting Pin Oaks is perhaps questionable, but it is easily grown from acorns and is available from most nurseries. The wood was once used to "pin" barn beams because of its toughness.

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