Elms: The Giving Tree

For thousands of years, the American elm (Ulmus americana) was the go-to tree for building supplies and home furnishings, kind of a Home Depot of the forest.

For the Haudenosaunee (Iroquois) and other First Nations peoples, it provided roofing and walls for longhouses measuring over a hundred feet long, as well as for smaller dwellings and outbuildings.

Elm also furnished top-notch material to make items as diverse as ladles, canoes, trays, snow shovels, grain scoops, baskets, and containers of all sizes.

Before Dutch elm disease reached the New World, the bark of these massive trees furnished native peoples an all-purpose building material. Prodigious sheets of elm bark could be peeled in springtime, anchored flat and dried in the sun to become the equivalent of plywood. Yet fresh elm bark, which has the consistency and texture of thick, wet leather, could be bent, sewn and tied into an array of useful articles. Once dry, these utensils, containers and other items became hard and held their intended shape.

In the rich flood plains of eastern North America preferred by elms, these fast-growing trees attained their largest proportions, growing a hundred feet tall, with trunks reportedly greater than ten feet in diameter. Elms typically shed lower branches early in their life. They also tend toward developing upright, vase-like forms. This all results in expansive, smooth lower trunks with ample knot-free bark, which back in the day was perfect for home-building and other projects.

The Haudenosaunee in particular made extensive use of elm “plywood.” Sheets of bark would be laid out flat where holes could be easily punched or drilled along the edges before the bark dried in the sun. In a few days the sections were ready to lash to a log framework such as a longhouse which might house dozens of families. Elm bark was also used to construct large grain bins, and European explorers wrote about their amazement at finding Haudenosaunee villages stocked with tens of thousands of bushels of corn stored in elm bark bins and cribs.

I’m told that to a large extent, the Haudenosaunee made canoes of elm bark, rather than from birch, which did not grow in abundance in much of their territory. Being a lot heavier, elm canoes were not portaged, but rather served as a way to travel between villages along rivers. Birch canoes were used by the Haudenosaunee, of course, but generally were made up north.

Fresh elm bark can easily be bent and folded to make utensils and containers which hold their shape once dry. Every spring I peel a small elm, or even just a branch, to make a few rattles, spoons and baskets. Between late spring and mid-summer, elm bark can be removed with no more effort than peeling a banana. To be sure, that “peel” is heavier, but it lifts off the tree with ease. Elm bark shrinks as it dries, but unlike the bark of many other species, doesn’t readily split.

In the late 1920s, the fungal pathogen known as Dutch elm disease (DED) made its way from Europe to North America, opening a sad episode the history of native elm species. Disease spores are spread by two bark beetles, one native and one introduced, and the DED fungus clogs xylem tubes that bring water and nutrients up to the leaves. Where elms grow crowded together, as was the case in many towns and cities, it also spreads through natural root grafts. This is the way in which whole elm-lined city streets became denuded in a matter of a few years.

Small to mid-size elms can be found throughout their native range, from Nova Scotia south to northern Florida. In the Adirondacks, where soil type rather than climate often limits where elms can grow, isolated stands of elms often see fewer DED infestation cycles. These stands may grow for several decades, becoming fairly large size before they succumb.

Some of North America’s largest old elms can be found in places such as New York City’s Central Park and on the campus of Penn State University. These old-time elms exist thanks to a regimen of systemic fungicide injections and insecticidal sprays. In fact, Penn State clears its campus for a couple of days each year so helicopters can spray its elms.

Chinese and Siberian elms are very resistant to DED, but neither comes close in size or shape to American elms. Since 1983, the Elm Research Institute in Keene, NH has promoted “American Liberty Elms,” some of which have resistance to DED, but are not immune.

Hybrids between Chinese and American elms have fair resistance, but they still can’t fill the shoes, as it were, of Ulmus americana.

Although it may be a long way off, it’s possible we’ll again see massive elms like those whose bark once covered longhouses. I sure hope so.

Photo of American elm tree courtesy Wikimedia user Msact.