Above: An elm-lined street in St. Paul, MN, before most of the trees were killed by Dutch Elm Disease.
Although the American elm persists in forests and pockets of cities and towns, Dutch Elm Disease wiped out many of these stately trees in the early 1900s. Let’s look at some “famous” elms in history, and what you can do to monitor and protect American elms that you might be stewarding.
Indiana’s first capitol in Corydon, Indiana, had a famous elm. According to Harrison County Visitor’s Bureau, in 1816, Indiana delegates met under the spreading branches of one of the largest trees of its kind in the world to draft Indiana’s state constitution. Its branches have since been trimmed and the trunk preserved, which is today encased in a large sandstone monument. Dutch Elm Disease killed Indiana’s “Constitution Elm” in 1925.
USDA’s Trees, the Yearbook of Agriculture, 1949, describes several elms of national recognition that were associated with famous people. My suspicion is that few, if any, of these trees remain, but I am unaware of their fate.
There was a Washington Elm (reported to be planted by George Washington, or under his direction) near the senate wing of the U.S. Capitol in Washington, D.C. that survived until 1948.
There was also a famous Washington Elm in Cambridge, MA, under which the leader of the American Revolutionary Forces assumed command in 1775. Several true descendants of the tree were planted in multiple locations.
The John Quincy Adams Elm was planted on the White House grounds during the administration of President Adams. The Grant Elm was planted by President Grant in 1870 on the lawn in front of Woodstock Academy in Connecticut. The Buffalo Bill Elm near Le Claire, Iowa, was a tree under which William F. Cody played as a boy.
And now to the tragedy of Dutch Elm Disease (DED).
“Although most cities contain an Elm Street, very few cities can claim having mature American elms on that street, or any other,” wrote Janna Beckerman, now Purdue Professor Emerita. “The American elm was a premier street tree: Tolerant of compacted soil, fast-growing, long-lived, and with a beautiful vase-shaped form.” She said its very popularity led to its downfall.
DED is caused by one of two species of fungi. Certain beetles feeding on infested trees can pick up the fungus and carry it to infect new, healthy trees. If several elm trees are growing near each other, the disease can also pass from one to the other through root grafts.
American elms are more susceptible to the disease than Slippery (red) elm and other elms. “Although immunity does not appear to exist in native elm populations, select individuals or cultivars have been identified and propagated,” said Beckerman. “European and Asian elms are less susceptible than American elm.”
Beckerman described how the disease progresses: “The first symptoms of Dutch elm disease are often overlooked due to the position of wilting leaves on branches in the upper canopy of the tree. Affected leaves usually turn yellow, then brown, and fall prematurely, although some leaves may remain attached. Upon losing its leaves, a branch quickly dies. Trees infected late in the summer or early fall usually survive only to rapidly succumb to the infection the following year. The rate of the infection varies, but an entire tree can die within a few weeks. DED-infected trees can be readily identified by brown streaks in the outer sapwood after the bark is removed.” She concluded by saying conclusive diagnosis of DED requires laboratory testing.
To protect remaining elms on your property, Beckerman recommended sanitation, root graft disruption, pruning, fungicide injection, and planting DED-resistant elms. For additional details, see Beckerman’s original article at https://purduelandscapereport.org/article/dutch-elm-disease/.