- Historic Sites
Elm Street Blues
A HERITAGE PRESERVED Since 1930, more than half of America’s splendid elm trees have succumbed to disease. But science is now fighting back and gaining ground.
October/November 1986 | Volume 37, Issue 6
Some of these cities are following a program recommended by the Elm Research Institute, a nonprofit organization with headquarters in Harrisville, New Hampshire. In addition to the removal of deadwood, the institute’s procedure involves injecting elms with a fungicide. It is a preventive measure, carried out annually. After eleven years of this program, the rate of loss for treated elms has been less than one percent, says the assistant director, Barbara O’Brien. “There is no reason for a tree to be lost today,” she says. “It’s a crime when one goes.”
Scientists are now striving to produce a hybrid as much like Ulmus americana as possible.
The Elm Research Institute has been fighting for elms since 1964. That was when the founder, John Hansel, a Connecticut businessman, saddened by the loss of his own elms, wrote a letter to find out what was being done. In time he wrote ten thousand letters to scientists, conservation groups, and foundations. He was alarmed that, while efforts were afoot to save the redwood, and the whooping crane, nothing was being done to save the elm. Dozens of universities, foundations, and corporations joined him, enabling the Elm Research Institute to fund almost a million dollars in research over the past two decades.
That research has led to some impressive successes and tantalizing leads. Barbara O’Brien predicts that “one-shot immunization against Dutch elm disease is around the corner.” But that is only one of the solutions scientists are studying. So diverse is the research on Dutch elm disease—there are now more than three thousand published scientific articles—and so different the tactics, that every three years the institute sequesters the experts at a New England inn to debate the direction new research should take.
Today the third generation of researchers is working on Dutch elm disease: the first identified it after World War I in Holland; the second, Miller’s generation, uncovered the mechanics of the epidemic; and today’s scientists hope to lead the revival.
Each generation of researchers has also come to some disappointing dead ends. In the late 1960s, attention focused on a small wasp from France that drilled through bark and whose larvae fed on the beetle grubs. But the American bark proved too tough for the visitor. Currently researchers are pursuing ways to divert the beetle from the tree. The National Park Service in Washington, along with Lanier, is studying pheromone traps—luring the male beetle to his doom with the scent of the female. The Elm Research Institute is funding work to find an olfactory disguise for the elm, the theory being that beetles are attracted to elms, of all trees, by a certain smell, and that if elms smelled like maples, or even like garlic, the beetle would fly on past with its harmful fungus.
Outside the laboratory, the elm, which some had marked for extinction, is thriving. Dr. Richard Campana, formerly the chairman of botany and plant pathology at the University of Maine, Orono, has spent much of his life studying Dutch elm disease, traveling across the country to visit regularly with about fifty “patients.” He recently finished a two-year study of areas where the disease first hit fifty years ago. He reports: “The elm is coming back and has been coming back every year. There are millions of elms coming up around the outskirts of the cities. It’s a weed. In New England you can’t keep it down. If you have a garden, you have to weed it out every year.”
In some forest somewhere a new strain of American elm resistant to Dutch elm disease may be evolving, but such evolution takes thousands of years. Arborists are trying to hurry the process by developing new disease-resistant hybrids. One such botanist is Dr. George Ware, who cross-fertilized a Japanese and a Chinese elm and produced a hybrid that seemed resistant to the disease. He has been growing generation after generation of seedlings at the Morton Arboretum outside Chicago in an effort to produce a tree as much like the beloved Ulmus americana as possible. Dr. Eugene Smalley, a plant pathologist, after twenty years of research, has created the first elm from American parents that is resistant to the disease. The Elm Research Institute in Harrisville now has ten thousand clones of Smalley’s hybrid under cultivation and already has thousands of orders. The institute is calling the tree the American Liberty Elm. However, it is not known if the hybrid will be resistant to other diseases, like elm phloem necrosis, a highly virulent virus now infecting trees in upstate New York.
The memory of elm-shaded childhoods, and trees that were landmarks in their time, does not fade easily. Many people are committed to restoring the American elm to the landscape. Standing in the Harrisville laboratory, O’Brien surveys the miniature forest-in-waiting —trees that may one day be one hundred feet tall. “The early settlers,” she says, “left us this beautiful country planted with the best of intentions in the world with this beautiful tree. And I think the very least we can do is to try to repair the damage, replant, and leave a legacy for the next generation that comes along.”