This is an excerpt from the book called ” NATIVE TREES FOR NORTH AMERICAN LANDSCAPES “ . Continue reading to learn more about White Oak-native Trees of North America , thanks to the author.
Quercus Alba
WHITE OAK
DESCRIPTION: Oaks suffer form a short-sighted demand for instant gratification in the landscape that often results in a misguided preference for trendy but short-lived exotics. As we tree planters gain the wisdom and patience of experience and begin to focus more on the potential immortality of our work, native oaks are the trees we turn to throughout most of North America.
Oaks occur naturally in vast numbers in each of the forty-eight contiguous states but Idaho, though cultivated oaks grow there. More than sixty oak species are native to the United States and Canada, and many more can be found in Mexico. Much of what I cover for white oak applies as much to the rest.
Just as maple is the official tree of Canada, oak has been selected as the national tree of the United States. And the tree that might claim to be the flagship species of the genus is white oak, the state tree of Connecticut, Maryland, Iowa, and Illinois. White oak is a dominant tree of many landscapes. It lives for several centuries under favorable conditions, becoming more massive and picturesque with every passing human generation. Like most oaks, it establishes from acorns sown by wildlife into openings caused by wind throw, fire, logging, or other disturbance, and grows slowly but relentlessly to become, after the first century or two, the lord of its locality.
The U.S. national champion white oak was the famous old Wye Oak, which grew in its own park, Wye Mills State PARK, Maryland, until a storm brought it down in June of 2002. Nothing else ever quite matched it, even though every portion of its natural range boasts notable and noble white oaks. It was 80 feet (24m) tall with a canopy that spread more than 100 feet (30m), and its huge limbs were supported by a hollow trunk 10 feet (3m) in diameter. Its enormous spreading crown was braced and cabled for many years to postpone its inevitable death from windstorms or lightning. Consequently it lived as it had since before the birth of the nation, well exceeding what otherwise would have been its natural life span, to awe every visitor who knew enough about trees to comprehend its antiquity.
LEAVES: White oak leaves show the classic rounded outline used by graphic artists everywhere to symbolize the genus. The logo of the Nature Conservancy, one of our finest natural heritage preservation organizations, consists simply of the silhouette of a white oak leaf. The leaves emerge white or pink in spring, turning medium green as they expand to about 7 inches (17.5) long. In fall they are among the most colorful of all oak leaves, turning various shades of crimson.
FLOWERS AND FRUIT: Oak flowers develop as the leaves expand in spring. The axillary pistillate flowers are minute and not easily noticed, but staminate catkins, seen en masse from a distance, give the entire tree a veil of pastel green smoke. Oaks are wind-pollinated, so tremendous numbers of these catkins are produced to ensure that some of the pollen fulfills its destiny. Individual trees exhibit protandry and thus encourage cross-pollination of early-blooming trees by later-blooming ones.
The fruits are acorns, familiar to anyone who ever walked an oak woods in early fall. White oak is in the taxonomic subdivision of oaks known collectively as the white oaks (section Quercus, formerly subgenus Lepidobalanus or Leucobalanus; see the taxonomic discussion under Quercus shumardii). Acorns of oaks in this group ripen in one year. The acorns will sprout without a dormancy period and begin to germinate as soon as they fall from the tree. They are among the very best sources of food for wildlife and are gathered and hoarded by birds and rodents.
BEST SEASONS: FALL (for the rich fall color and the acorn crop, which draws a fascinating array of wildlife like a magnet). SPRING (when the tiny new leaves and staminate catkins combine to lay a pastel tint of the artistic superstructure of limbs). WINTER (for the character of the tree’s architecture and bark) and SUMMER (as a superior shade tree).
NATIVE AND ADAPTIVE RANGE: The natural range of this species is a nearly perfect square, the points of the square being Minneapolis, Minnesota; Augusta, Maine; Brunswick, Georgia; and Houston, Texas. This range extends across southern Ontario and the edge of Quebec, and trees from northern sources can be planted safely in USDA zone 3.
CULTURE: Give white oak a neutral to acidic soil. Water and fertilize young trees to promote double flushing (acceleration of growth by developing two years’ worth of shoots in one year). Control competition from weeds and turf. Then wait. Planting a white oak is symbolic of faith in the future and should not be undertaken by anyone with plans only for the present human generation. As people grow older and become more conscious of their legacy for humanity, they tend to plant white oaks.
Kids plant them sometimes too, because propagation is so simple and fun. Healthy acorns (those not infested with insect larvae) should be planted on their sides in fall, as soon as they mature, and protected from squirrels and mice for the entire first growing season. If the young seedlings are being grown for eventual transplanting, place the acorns in a sealed bag in the refrigerator until the hypocotyls (primary roots) emerge and lightly pinch back the tips of those roots before planting. This will encourage a branched root system, without which oaks can be difficult to transplant.
Unclipped acorns grown in pots tend to develop long, circling roots, which become girdling roots years later in the landscape. Some container nurseries fight this problem by using deep, ribbed pots. I prefer root-control pots coated inside with copper, or bottomless pots (on raised benches or pallets), which cause air-pruning of the taproots. The best solution, if possible, is always to plant the acorn directly where you want the tree to be growing for the next five hundred years.
PROBLEMS: Many of the common problems discussed here apply to other oaks and for the sake of brevity will not be fully repeated elsewhere. White oaks will not survive long in shade and are intolerant of poor drainage and alkaline soil, which cause chlorosis. Old trees are extremely sensitive to construction disturbance within their root zones and do not appreciate the conversion of a forest duff groundcover to competitive turf. The acorns can be a litter problem, but birds and squirrels usually clean them up before winter. Anthracnose (Gnomonia quercina) disfigures many oaks during wet years and can be particularly severe on white oak, but it generally does not cause permanent damage. New foliage that develops in summer as a second growth flush can be particularly susceptible to mildew from Microsphaera species and related fungi. Oak tatters, a physiological foliage problem, is speculated to be caused by herbicide damage or cold temperatures during bud break.
As the preeminent genus of hardwood trees in North America-that is, the genus with the most species, the most individual trees, and the widest distribution-oaks in general are subject to many other nuisance diseases and insects that are generally not serious. They are famous for the beauty and variety of the galls they support, most of which are harmless.
The crown of an oak sometimes has forks or whorls of limbs that can affect the structural strength of the tree. These are formed from development of clustered sub-apical buds, which tend to be dominant over the median lateral buds scattered along the twig. Whorls may be thinned and narrow forks trimmed to a single leader when the tree is still small to encourage development of a strong crown.
A benign bark fungus, Corticium patch, causes interesting sooth patchy patterns on the bark of this and some other white oak species. Damaged and overwatered roots are subject to decay by the fungi Armillaria tabescens, A. gallica, and A. mellea. Some trees die quickly from Armillaria, while others persist in a seemingly healthy condition until their root systems are nearly gone and they fall onto the nearest house. The most well known oak disease, ok wilt (Cerutocystis fagacearum), is not as virulent on white oak as it is on some other species.
Young oaks of all species can be defoliated by yellow-necks (Datama minstra) and other gregarious caterpillars. If they are newly transplanted or otherwise stressed, they will be prone to attack by chestnut bores (Agrilus bilmtion). Sucking insects like lace bugs (Corythucha arcuata), over (Olgonycbus bicolor), and various scales can weaken trees. And unless you have big dogs or tall fences, deer are bound to take their toll on young trees. Livestock, chiefly houses and goats, can girdle centuries-old trees in barn-yards unwittingly destroying the shade needed so badly in the heat of summer.
All oaks are cake and ice cream to the notorious Gypsy moth (Lymantria dispar), introduced from Europe in the 1860s. This insect defoliates more than 6000 square miles (15,540 sq. km) of forest each year, killing some trees and stressing others. Oaks are our most important hardwood timber genus, so many forestry scientists are working furiously to bring this epidemic under control. Specimen trees may be sprayed by an arborist, if necessary, to minimize Gypsy moth damage.
A better long-term solution will be to enlist the aid of biological controls such as the fungus Entomophaga mamage, which is showing great success in controlling this pest in experimental evaluations. Other promising tools for control include the braconid endoparasite Rogas lymantriae, an icheneumon fly; Cotesia melanoscela, a small parasitic wasp; a nucleopolyhedrosis virus marketed under the name Gypchek; and several parasitic Micompordia organisms.
Oaks hold great promise for landscaping but have been held back due to several other perceived problems. Until recently they were difficult to propagate from cutting or even by grafting, so that exceptional selections could not be replicated easily. Many oak species are difficult to transplant as well, but root-training techniques used in modern nurseries have solved this. Old oaks growing on upland sites also often experience problems related to the sudden increases in competition and irrigaoon in newly established lawns. All of these challenges can and should, be overcome.
CULTIVARS: A few variant forms of white oak are described in the literature. ‘Jasper’ is a compact selection from Indiana with dependable fall color. I selected a deeply lobed form a few years ago from a tree near the tomb of Abraham Lincoln and gave scionwood as a gift to Dick van Hoey Smith, director of the Trompenburg Arboretum in Holland; he was very pleased with it and named it ‘Lincoln’. It is being distributed mostly in Europe. ‘Elongata’ is a form with long narrow leaves, again seen mostly in the arboreta of Europe. I have several other trees under evaluation.
White oak can be hybridized with other oaks in its subgenus, and some of the hybrids are magnificent. ‘Crimson Spire’ is a fastigiated selection of Quercus Χ bimundorum, the hybrid of white oak with the upright European oak (Q. robur ‘Fastigiata’). I have studied hybrid oaks for three decades and have selected several white oak hybrids for potential release to the nursery trade. The first of these be released, ‘Atlas’, is a superior cultivar of Q. Χ saulii, the hybrid of white oak with chestnut oak (Q. montana).
SIMILAR AND RELATED SPECIES: Several other white oak species are common on the West Coast. Garry oak (Quercus garryana) is the white oak of the Pacific Northwest, ranging from northern California north into western Canada. It grows for me in Illinois, though very slowly. Valley oak (Q. lobata) and blue oak (Q. douglasii) are common in California. All these species can be grown under cultivation in the East, north at least into USDA zone 6, but they much prefer the climate of their native region.
A few European oaks are common in cultivation. These include sessile oak (Quercus petraea), Hungarian oak (Q. frainetto), and especially the common European, or English, oak (Q. robur) and its many cultivars. Many other members of the white oak group (section Quercus) grow in North and Central America, Europe, Asia, and northernmost Africa, and many additional oaks grow in the Western Hemisphere, including red oaks (section Lobatae, formerly subgenus Erythorbalanus) and intermediate, or golden, oaks (section or subgenus Protobalanus). Worldwide there are several hundred species and countless hybrids within the genus, including the additional Asian section or subgenus Cyclobalanopsis, and many more among the closely allied tanoaks (Lithocarpus), Oaks are in the same family as chestnuts (Castanea) and beeches (Fagus).
COMMENTS: Ancient white oaks probably appear on more inventories of historic trees, over a broader area, than any other tree species. Due to their predominance in the landscape within their broad range, many historic events have taken place near them. And due to their longevity, many have survived as living witnesses to those events.
The Brompton Oak shaded a Union field hospital during the Civil War battle of Fredericksburg and still stands today. The Lincoln Vault Oak shaded the choir that sung at Lincoln’s funeral but was destroyed in 1992 by a misguided public agency charged with managing the historic site in which it stood. Subsequent dissection confirmed that it was solid, vigorous, and could probably have borne witness to that had funeral for another few centuries if human stewards had not removed it.
The Pemberton Oak in Bristol, Tennessee, saw Revolutionary War action. Fortunately, the generations of humans that live around it after that time were appreciative of its history; it survived in silent testimony until it was taken by a storm in 2002. Among the most impressive white oaks is the Richards Oak in Cecil County.
Maryland, which was depicted as landmark on a map made for William Penn in 1681. It subsequently served as camp shelter for General Lafayette in 1781 and for a cavalry until during the Civil War By 1965 it shaded an area 11.5 feet (34.5cm) across.
I once stumbled upon an impressive white oak in an old rural cemetery in southern Illinois. Subsequent research revealed the origins of the cemetery, named Hopewell Cemetery after the church that was built beside it in 1831. During the time of the Lewis and Clark expedition, a westward-bound pioneer family was camped at a nearby spring. Their young child died and was buried under what even then was a landmark tree, so that the family could fine the grave if they ever returned from wherever they finally settled. I don’t know if they ever did return, but other pioneers, taking the same wagon trail and seeing the grave followed suit with their own dearly departed and the cemetery came in existence. The Hopewell Oak is there today, off a country road a few miles west of Pinckneyville. Thousands of such series abound in written and oral history.
Think of a century-old white oak as being at the same life stage as twenty-five-year-old human. Then think of us at seventy-five, and at one hundred and use the same equation to view the life stages of your oldest trees. A white oak grows for about a hundred years lives for another hundred years and mellows and declines for another hundred to two hundred years or more. But it can do so only if each human generation that comes and goes during its life span respects, protects, and honors it. We all inherit such responsibilities.
