The American Chestnut Tree

Samuel B. Detwiler
Reprinted from American Forestry, October, 1915.

Our native chestnut tree is one of our best known and best loved trees because of its beauty and utility. It grows from southeastern Maine west to southern Michigan and south to northern Virginia, southern Indiana and along the Appalachian Mountains to northern Georgia, Alabama and Mississippi. The bright foliage, attractively-shaped leaves, toothsome nuts and stately form give distinction and character to this highly valuable commercial tree of our forests.

The finest chestnut trees in the world are found in the southern Appalachian Mountains, especially in western North Carolina and eastern Tennessee. A tree with a diameter of 17 feet has been recorded from Francis Cove, North Carolina. Commonly, the mature trees are 3 to 5 feet in diameter and 60 to 90 feet in height, but there are numerous specimens 7 feet or more in diameter, 100 to 120 feet high. In Pennsylvania, New York and the New England States chestnut trees have mostly grown from stump sprouts, and are therefore comparatively small.

When growing in the forest, a chestnut tree will bear only a moderate amount of shade, and the crowding of adjoining trees causes the early death of the lower branches. For this reason forest-grown chestnut trees nearly always have long, straight, clear trunks, branching out into rather small, rounded tops. In the open the trunk is short, dividing into three or four heavy horizontal branches to form a broad, beautifully rounded head.

The chestnut has many features that distinguish it from its neighbors at every season of the year. Its grayish brown bark somewhat resembles that of the red oak because of the broad, flat, irregular ridges, but is readily known by the darker gray color, deeper fissures, and the smaller and more flaky scales of bark on the ridges. Very young trees have smooth bark. Later the ridges develop, separated by shallow fissures, and in old age these fissures become quite deep.

The buds are one of the best means of identifying this tree in winter. They are dark brown, about one-quarter inch long, egg-shaped but usually sharply pointed. The buds stand singly on strong-growing branches. Every fifth bud stands directly above the one from which counting begins, and if a string is drawn from bud to bud it will form a spiral, passing twice around the branch from the first bud to the fifth one.

After most of the trees have well developed foliage, but before the oaks have put forth their leaves, the chestnut buds open and the tiny leaves unroll. Though inconspicuous, there is grace and beauty in the artistic symmetry and delicate coloring of the baby leaves—rose, yellow and exquisite shades of green. On short branches that bear the fruit, the leaves form a leafy star, giving variety to the appearance of the foliage.

In form the leaves are slightly like those of the beech. They are six to eight inches long and about two inches wide, wedge-shaped at the base and tapering to a sharp point. The margins are coarsely toothed and the veins prominent and regular. The “ant cows” (plant lice) love to feed along the veins on the lower surfaces of the chestnut leaves. In the Fall the leaves assume soft shades of yellow and red, but soon lose their brilliancy.

Early in July the chestnut tree becomes one of the most striking features of the landscape. Long after other trees have bloomed, it suddenly blazes into a wealth of odorous, cream-colored blossoms. These are the clustered catkins of the pollen-producing flowers. The flowers that produce the nuts are separate from the others and much less noticeable, because they consist of small spikes with a few green, scaly blossoms. These two kinds of blooms do not usually appear at the same time on one tree. The wind carries the pollen from tree to tree and thus effects cross-pollination.

Two or three, or sometimes only one, of the nut-producing flowers are fertilized and grow into prickly burs. At first the young burs are very small, but by the middle of August they are full-sized. The sharp spines which make the bur a sort of vegetable porcupine are Nature’s protection against injury to the sweet nuts until they are fully ripe. The Indians called the Chestnut tree “O-heh-yah-tah”—“the prickly bur.” The first heavy frost of Autumn causes the bur to separate into four parts, disclosing two to four shining nuts resting in a bed of soft brown velvet.

Chestnut trees do not grow well if the soil around their roots is disturbed, as is shown, in regions where blight is not prevalent, by the dead tops of many trees in closely grazed pastures and on the road sides. They are easily injured by fire and have many insect enemies. Various species of borers injure the bark, the wood is very apt to be perforated by small worm holes, the foliage is frequently injured or destroyed by leaf rollers and leaf-eating insects, and the nuts are often infested with the chestnut weevil.

The most serious enemy of the chestnut tree and one that apparently means its ultimate extinction in this country is the chestnut bark disease or “chestnut blight.” All species of chestnut and the chinquapin are susceptible in varying degrees to the bark disease. The chestnut bark disease was brought to this county from China or Japan, and the Chinese and Japanese chestnuts are highly resistant. The chinquapin is slightly resistant, but the American and European species of chestnut have thus far shown no power to withstand the disease.

Although comparatively little has been heard about the chestnut blight in the past two or three years, there is no evidence that it is progressing more slowly or that it is less virulent than formerly. The bark disease is generally prevalent from Maryland to Connecticut, as far west as the mountains, and scattered infections occur as far west as eastern Ohio and eastern West Virginia, and in southern Virginia and North Carolina.

The chestnut tree is noted for rapidity of growth and for its ability to sprout freely. The rate of growth varies with the conditions under which it grows. An average growth in diameter is about one inch in three years. Under normal conditions the chestnut tree lives to a great age. It grows on a great variety of soils, but does best on porous soils of moderate depth and fertility. It is well suited with rocky hillsides and gravelly or even sandy soils, but it is seldom found on limestone soils.

The chestnut produces great numbers of vigorous sprouts from the stumps of young and middle-aged trees. These sprouts grow more rapidly than seedlings during the first thirty years of their life, and in the past, because of this valuable characteristic, the chestnut has been one of the most profitable trees in the farmer’s woodlot. It is easily grown from seed but natural seedling growth is usually not abundant because the nuts are so highly prized for food by squirrels, mice and other animals, as well as human beings. In view of the relentless destruction of the chestnut by the bark disease and its many other enemies, the planting of this species is not advisable.

The wood of the chestnut is of a brownish color, light in weight, coarse grained, fairly soft, of medium strength, easily worked, and the grain has a pleasing pattern. It is durable in contact with the soil, on account of the high tannic content, which ranges from five or six per cent in young trees to ten to fourteen percent in very old trees. The wood has a great variety of uses.

The nuts of our native chestnut are superior to the European and Japanese species, and to a less extent, to the Chinese. Chestnuts are an important article of food in Italy and some other foreign countries. They are made into flour from which bread is made. They are also served for food in a variety of other forms and possess a high nutritive value.

There are a number of varieties of cultivated chestnuts mostly derived from the European chestnut. Until the advent of the blight, chestnut orchards for the production of nut crops offered a source of revenue from waste land. Chestnut orchard trees must be grafted, as varieties do not come true from seed.

The chinquapin is the chestnut’s nearest relative, native to this country, that assumes tree form. It is usually a shrub and the leaves and burs cause it to resemble a chestnut in miniature. The nuts are small and shaped like an acorn, but are very sweet and delicately flavored. It is possible that a variety of chestnut immune to the bark disease may be bred by crossing the Japanese or China species with the chinquapin, creating a variety superior to any which now exists.

See also "Chestnut in the Future", also reprinted from American Forestry, October, 1915.