Prairie Expedition® American Elm

Prairie Expedition® is the registered trade name for the ‘Lewis & Clark’ selection of American elm, introduced by North Dakota State University in 2004. It develops a broad, rounded to spreading vase-shaped canopy with dark green foliage that turns yellow in fall; published nursery dimensions are about 55 feet high by 60 feet wide. The cultivar is valued for resistance to Dutch elm disease, though resistance does not guarantee immunity. [J.F. Schmidt’s cultivar sheet](https://jfschmidt.com/wp-content/uploads/2023/02/prairieexpeditionelm.pdf) lists the selection’s form, dimensions and zone rating; [Colorado State University’s elm cultivar profile](https://webdoc.agsci.colostate.edu/bspm/ElmCultivatorInformation.pdf) documents its NDSU origin and disease history. ## Landscape Use Use this large shade tree where its mature canopy has room to spread, such as parks, broad lawns and spacious streetscapes. Its spreading crown provides substantial summer shade as it matures. ## Growing Conditions The cultivar is described as extremely cold hardy and suited to harsh urban environments. Allow for a wide crown when placing it near buildings and paved areas. ## Maintenance Preserve room for the mature canopy and monitor the tree as it establishes. Inspect elms regularly for signs of stress or disease; cultivar resistance is not immunity.