IT WOULD NOT BE RIGHT TO CALL JOE DICKEY A SENTIMENTALIST. With a doctorate in physics, a full career in Navy research labs, and years more of teaching at Johns Hopkins University and elsewhere, Dickey has a clear-eyed view of the world. When he and his wife bought this land in southern Anne Arundel County in 2002, they had no plans to become chestnut farmers.

But when they decided to buy the adjacent 22 acres of farm fields to add to their original 5 acres, they found themselves on the tax books as farmers. Either that, or they owed the government a lot more money.

Tall, outdoorsy, and rugged-looking, Dickey liked the idea of becoming a certain kind of farmer. What kind of farmer wasn't clear, but he ran across an article in Science News that intrigued him. It described a grand experiment with a grand old tree: the American chestnut.

Most of us, including Dickey, who just turned 70, are too young to remember the age of the American chestnut. We do — many of us — know the story of its demise.

In a field of dreams, chestnut trees selected from different genetic pools (left bottom) soak in the southern Maryland sun. Physicist Joe Dickey (left top) never thought he’d be a chestnut farmer. An accidental expert, he points out the heart-shaped stipule on a mostly Chinese chestnut tree (right top). Nutritious brown nuts (right bottom) once sustained both wildlife and mountain folk. Credits: Jack Greer.

The American chestnut once graced forests all along the Eastern seaboard, from Maine to Georgia. For thousands of years it supplied large brown nuts, wrapped in an uninviting spiky green bur. The tree fed all kinds of wildlife and then all kinds of humans. For hundreds of years it supplied good wood as well, for log cabins, for furniture, and in the end for railroad ties, mine shafts, and telegraph and utility poles.

Then in the early 1900s chestnut trees began to die. The chief forester at the New York Zoological Park (now known as the Bronx Zoo) first puzzled over dying chestnuts in 1904. In 1906 scientists identified this new fungus, and at first they thought they could control it. They tried selective cutting and aggressive trimming. Infected chestnut trees resembled amputees, until they finally succumbed and were cut down. By 1908 the New York Times declared, "Chestnut trees face destruction."

In the years following, the blight spread. As early as 1911, the fungus had found its way to nearly a dozen states. Some experts continued to argue that a Herculean effort to stay ahead of the disease could still save many of the American chestnuts that remained, especially the large stands in Virginia and the southern Appalachians.

In the end, even these diehard tree warriors threw in the towel. It was a rout. By the 1920s and 30s, the chestnut blight had conquered just about every forest in the U.S. Only a few stands seem to cope with the blight, in lower Michigan, for example.

Here, in Chesapeake Country, a few sizable trees remain. Mostly we have only old photographs, old tools, old carvings. One relic is a totem shaped from chestnut wood given to early settlers by Bay-area Indians. It's kept in the American Portrait Gallery, where its dark iconographic wood still gleams, handled by many hands.

Old photographs, old stories, a few survivors. But also green shoots — reedy saplings that the stumps of otherwise dead chestnut trees send up year after year. These green scions should be rays of hope, but after they reach about the height of a human, the ever-present blight finds them. And kills them.

Researchers tell us that sprouts from these old chestnut ghosts can't keep coming back forever.

This is where Joe Dickey comes in. When Dickey decided to become a part-time farmer, chestnut trees became his crop. It's a crop he'll never harvest.

His trees actually belong to the American Chestnut Foundation. Along with many others, he's working with the Foundation to see if he can get chestnut trees to grow — and survive.

In 2005 they brought nuts to plant, and when the time comes they will come and take the best of what's left to propagate the next generation. This leaves Dickey with a 10-year commitment and a lot of work to do. To begin, he marked out 10-foot centers over large stretches of his newfound fields and sweated with four or five volunteers from the Chestnut Foundation to plant 200 nuts. Each nut represented the best offspring from the previous generation.

With green shoots sprouting in the ground, he could have stood back and watched his crop of chestnuts grow, except for the deer. And the raccoons. The only thing that stopped deer from grazing on his tender seedlings was a fence made of mesh some eight feet high — high enough that they wouldn't leap over it.

The raccoons were more determined, and smarter. Dickey put plastic tubes around the seedlings, and thought he'd solved the problem. But the raccoons simply dug beneath the plastic tube until the sprouting nut dropped into their humanlike hands. To stop the digging, he laid large mats of chicken wire over the plantings. That seemed to work.

As the growing season progressed, he had to keep down all the other things that grow in a field. He had to mow. And mow. He does this himself, a physicist-farmer on the back of a tractor.

The next year, he planted another 200 trees, and the following year he planted 200 more. He now has a chestnut orchard of some 600 trees.

These are not ordinary chestnuts. Only two or three percent count as pure American chestnut, and these are almost certain to die. Most of his trees hold a genetic mix of different breeds, carefully coded and recorded. This field of dreams is more like a big roulette wheel. The winning number will be the right genetic combination, the proper mix of disease-resistant genes and good growth.

The lucky numbers for this game come from two main sources. First, the American chestnut, with its penchant for towering trunks and spreading branches — a king of the forest. Second, the Chinese chestnut, which is hardy and disease resistant, but lower and bushier than its kingly cousin.

The object of the game is to have enough of the first genes to get a tree that resembles the American chestnut of yore, and enough of the second to keep that tree from dying.

So far, Dickey says, only the trees that are mostly Chinese seem able to survive. Good for a garden or backyard, perhaps, but no forest dweller, no towering giant, no source of abundant lumber. No storied chestnut tree.

Next spring, in 2010, experts from the American Chestnut Foundation will come and inoculate each of his five-year-old trees with a particular strain of blight (fungus). Then they'll wait a year or two to assess the trees' health. To continue this breeding experiment, this race against time, they'll select the ones that are doing the best. Say 2 or 3 out of 100. They will destroy the rest. Cut them down and burn them.

"It's a little sad, isn't it?" Dickey says, his eyes looking off beneath heavy eyebrows. Perhaps he can be sentimental after all.

The experiment will go on. There are about three or four such orchards in Maryland, he thinks. One in the coastal plain (his), one in the Piedmont, and at least one in the mountains. Each orchard is a roll of the genetic dice. Each temporary chestnut farmer hopes to take breeders one step closer to a winner.

For now Dickey's trees look great, row after row. He can pick out the young trees that are all Chinese. The leaves are wider, thicker. Many are bearing nuts, carried in those bristly green porcupine cases. Dickey says it's not likely that any of these trees have seen the more virulent fungus strains, strains that almost certainly hover nearby. The blight keeps hanging around, year after year, decade after decade.

After a century of hope and struggle, modern breeders like Dickey are betting their money, sweat, and labor on a winner — a survivor that could bring towering chestnuts back to the forests of the Bay watershed and beyond.

For more about chestnut trees, see Susan Freinkel, American Chestnut: The Life, Death, and Rebirth of a Perfect Tree, University of California Press, 2007.