A New Chestnut

This month hundreds of volunteers along the Appalachian Trail will trade excited e-mails detailing when they plan to pollinate their chestnut trees with special pollen—one more step in a twenty-year effort to restore the American chestnut to its majestic place in the northeastern and mid-Atlantic forest. Until a century ago billions of American chestnuts came into flower before the start of July, making the hillsides they favor look buried in snow. As tall as the tallest oak, with a diameter of up to ten feet in a clear field, the chestnut made up fully a quarter of the forests in its native range, from southern Canada to Georgia.

In America as in Europe, the chestnut was the "bread tree," providing a staple that could be boiled and mashed to replace potato as a starch, ground into flour to make noodles or bread (a favorite use of the Cherokee, who made chestnut cornbread), or eaten out of hand, either raw or roasted, for a nutritious, filling snack. In October the vast stands provided an almost limitless supply of free food, dropping nuts that glistened like gemstones and fed not only people but also wild turkeys, pigs (whose ham made Virginia famous), and other animals that were themselves important foods. Chestnuts, easy to dry, gave Appalachian families a source of income and a way to survive the winter.

Creamy, slightly crunchy, delicately sweet without seeming starchy or bland, fresh American chestnuts taste almost like fresh water chestnuts, to which they aren't related. This was one of several revelations I had recently when I tasted "Americanoid" chestnuts, as the enthusiastic grower calls his hybrid American-Asian nuts—an advance sample of what all those volunteers are working toward (and available to anyone by phone or Internet order). Often no bigger than large marbles, American chestnuts have a relatively high ratio of surface area to volume, which enables them to convert starch to sugar faster than do the European and Asian chestnuts we are used to—chestnuts that have been bred to be big. American chestnuts are intensely flavored nuggets by comparison.

Other revelations: American chestnuts have far softer shells (which are easy to cut or bite through) and are miraculously free of the bitter skin that stubbornly clings to more familiar chestnuts. Cut in half and cooked for a few minutes in a microwave oven, they practically leap out of their shells. Thus it is now easy to pair chestnuts, fresh or dried, with the many things they nicely complement, including roasted root vegetables, seafood soups, and—now in season where chestnut trees once reigned—asparagus.

This is an auspicious moment to become familiar with the virtues of the American chestnut. The goal of reviving the tree is coming into view faster than anyone expected twenty years ago, when a few researchers adopted a new approach to reversing one of the great environmental tragedies in American history. In 1904 a fungus was discovered on a chestnut at the New York Zoological Park: Asian chestnuts, which brought the blight, were resistant, American not. The blight caused by the fungus moved through forests at up to fifty miles a year. Lumber companies, shortsightedly assuming that death was inevitable, began clear-cutting chestnut forests, selling the valuable timber—light, rot-resistant, easy to work, handsome in paneling and furniture—for railroad ties and telephone poles. Many of the fences built along the Appalachian Trail under the Work Projects Administration were of chestnut; they guide hikers to this day. Any natural resistance the forests may have harbored was lost in the clear-cutting. By 1950 nine million acres that had been covered with American chestnuts were covered with gray stumps. Wildlife populations plummeted, and along with them the food they had provided. (Horse chestnuts, being another species entirely, were immune from the blight. Their shiny nuts encased in spiky burrs resemble true chestnuts, but the nuts, called "buckeyes" in America and "conkers" in England, contain bitter tannins and sufficient acetone to make them potentially toxic.) A free subsistence crop disappeared from Appalachia, where poverty had long been another blight.

The revival of the American chestnut could catalyze the first large-scale success in restoration ecology, which aims to bring entire ecosystems to working health. This branch of ecology, still young, differs from movements such as permaculture, which encourages people to devise strategies to make healthy ecosystems flourish and endure. (Like sustainable agriculture, with which it overlaps, permaculture looks for ways to let people live off the land without fundamentally altering it.) Restoration ecologists have looked to ruined ecosystems such as strip-mined land and watersheds wrecked by logging—challenges requiring help from governments and landowners, who usually don't want to give it. Restoring the chestnut forest is a more straightforward goal.

The chestnut was the challenge facing early-twentieth-century American botanists. For decades, however, chestnut blight, which kills by girdling the tree with cankers that work inward and choke off its food supply, resisted all attempts to keep it in check or circumvent it. Because the fungus that causes it lives in the bark of other trees, such as oak and ash, without killing them, the blight still thrives in the chestnut's original range, killing off chestnut seedlings as they reach maturity. (Blight doesn't affect the root system; seedlings grow on stumps, sometimes for several years, before blight fells them.) Researchers crossed the blight-resistant Asian chestnut trees with American chestnuts and then, in classic fashion, crossed resulting generations, too, with Asian chestnuts, in order to introduce as many Asian genes as possible; no one knew which genes or how many conferred resistance. The work was terribly slow: it takes three to five years to prove that a cross is blight resistant. The crosses seemed certain to look like Asian trees, which are far shorter than the American species and shaped differently. And every cross failed. The intensive efforts that had begun in the 1920s petered out in the 1960s.

In the late 1970s Charles Burnham, a well-known plant geneticist, offered fresh hope. He hypothesized that blight resistance could be conferred by crossing American-Asian hybrids in the opposite direction—to American rather than Asian chestnuts, continually diluting out most Asian genes except those few that carried blight resistance. Burnham began working to create a blight-resistant tree that would preserve many more American characteristics, collaborating with Philip Rutter, a biologist and ecologist who was already trying similar breeding experiments.

The goal suddenly seemed decades, not centuries, away. The federal government had ended the chestnut program it had sponsored since the 1930s, so a group of independent researchers who had been seized by the chestnut dream formed the American Chestnut Foundation in 1983, with the grandiose aim of repopulating the Appalachians with American chestnuts. The smaller nuts of a true American chestnut, or something as close to it as possible, might not bring as high a price as the Asian chestnuts under commercial cultivation in California—but the benefits to wildlife populations would be incalculable. The oaks that took the place of chestnuts in many areas produce acorns irregularly, whereas chestnuts drop huge crops of easy-to-eat nuts year after year. The forests would benefit too. Rutter, who served as the foundation's president for ten years, estimates that a forest dominated by chestnut trees grows 30 percent faster than one dominated by oaks; the hyperactive chestnut produces sugar from sunlight all winter, staying bright green beneath its thin bark year-round. Also, the chestnut is a gorgeous tree.

From the beginning, volunteers, some with memories of the terrible blight, many others with only ideals and horticultural curiosity, supported the foundation—less with money (funding has always been minimal) than with planting and reporting. While the foundation tries to develop a resistant American chestnut that is just one-sixteenth Asian, volunteers in more than twelve states pollinate surviving American chestnut seedlings with pollen sent by Federal Express from the main farms, in Meadowview, Virginia. When the foundation distributes seedlings of the final hybrid, volunteers will cross them with pollen from the trees they have bred over the years, helping ensure local hardiness. The volunteers' guru is Fred Hebard, one of the foundation's few employees, a quiet and very tenacious plant pathologist who has devoted his whole career to the American chestnut.

Rutter is now a chestnut and hazelnut breeder and grower in Canton, Minnesota. It was his Badgersett Farms that shipped me those Americanoid chestnuts, which come from trees that are about 60 percent American. Badgersett sells fresh chestnuts for months after the harvest (the key to successful long storage, Rutter says, is very cold refrigeration).

Thanks to the work of volunteers, and thanks to techniques developed at Meadowview to speed testing, last spring Hebard planted the seeds of what he hopes will be his final-generation, fifteen-sixteenths American chestnut. Next year he will have the results of the first resistance tests. If they are good, he will begin the last years of testing, with the goal of supplying thousands of seeds and seedlings to volunteers up and down the country, who will plant starter groves. The volunteers will be "setting the species free again," Rutter says. "It can do the rest itself."

I had always assumed that the roasted chestnuts that appeared at our family dinners in October and November were nostalgic reminders of the Connecticut woods of my parents' childhood. My father recently corrected me. Chestnuts had long been gone from my parents' Connecticut; he and my mother knew them from the streets of New York. The Italian vendors who roasted chestnuts and scooped them into thick paper cones probably used the same kind my mother found at the supermarket (if a better grade)—Italian imports. Ill-advised long storage at room temperature guaranteed a high percentage of dried-out or moldy nuts, which also form part of my childhood memories—along with thumbs and forefingers burnt and blackened from impatient peeling.

The trials of cooking imported chestnuts, and also their brief and chancy seasonal availability, have limited their place in American cuisine. Other than in stuffing, their best-known use is as the sugar to make the medicine of brussels sprouts go down. If chestnuts can make brussels sprouts taste good, imagine what they can do for vegetables people actually enjoy. Roasted and chopped, chestnuts make a particularly good garnish for whole asparagus, whose acidity and slight fibrousness is complemented by the sweet chewiness of the nuts.

A perfect early-summer supper is my favorite asparagus dish, asparagi alla fiorentina—nothing more than asparagus boiled and then heated in the oven with melted butter and grated Parmigiano-Reggiano cheese, and topped with an egg fried sunny-side up. Diners break the egg yolk and let it run all over the asparagus. Chestnuts are a lovely addition; I have adapted a recipe from Nancy Harmon Jenkins's excellent Flavors of Tuscany. It demonstrates that sometimes nothing is better than butter—the best medium for chestnuts.

To prepare chestnuts as a garnish for the asparagi—and for many other kinds of vegetables or for stews—cut a dozen or so small nuts in half and microwave on a paper towel for two minutes. Let them cool a bit and remove the shells—this will be remarkably easy, and will sell you on the superiority of American chestnuts, if the sweeter and richer flavor isn't enough. Coarsely chop the nuts and set them aside. (If you want to serve plain roasted chestnuts, toast the cooked and shelled nuts in an oven at 375° until they start to blacken at the edges—a matter of just two minutes or so.)

For six servings of asparagus and eggs as a substantial starter or a light main dish, preheat the oven to 350° and have ready a shallow oval or rectangular ovenproof dish, half a stick (four tablespoons) of butter, a quarter cup of freshly grated Parmigiano-Reggiano, and six eggs, the freshest you can buy. Wash, trim, and peel two and a half pounds of fresh asparagus (I believe in peeling any spear that is thicker than a knitting needle). Bring unsalted water to a rolling boil, simmer the spears until they are bright green and still crunchy, about three to six minutes (the asparagus will soften as it rests and is reheated in the oven), and then drain the spears. While the asparagus cooks, heat half the butter in a small sauté pan until it foams. Pour the hot butter into the dish and arrange the asparagus over it. Season lightly with salt and pepper and scatter the cheese and chopped chestnuts on top. Heat the asparagus in the oven (but don't leave it in the oven for more than about seven minutes—long enough to melt the cheese and lightly brown but not burn the butter). Meanwhile heat a serving platter for the eggs. Melt the remaining butter in a frying pan and gently fry each egg over medium heat, basting the top with butter but letting the yolk thicken only slightly; transfer the eggs to the heated platter. Bring the asparagus and eggs to the table and let guests slide an egg on top of as much asparagus as manners permit them to take. (If you have timid guests, assemble the plates yourself.) Hot chestnuts should always inspire unmasked greed.

The American Chestnut Foundation Web site is www.acf.org; many state chapters have sites of their own, which are linked to the main site. Badgersett Farms is at www.badgersett.com.