Dutch Elm Disease in Wisconsin

Wisconsin holds a particularly significant place in the history of Dutch Elm Disease management in North America: the University of Wisconsin–Madison was the home institution of Eugene Smalley, whose foundational breeding program produced or contributed parental material to many of the most widely planted resistant elm cultivars in commercial use today. Active municipal management continues in Madison, Milwaukee, and other Wisconsin cities.

DED arrival and statewide impact

Dutch Elm Disease was first confirmed in Wisconsin in the late 1950s, with rapid spread through the state's elm-rich southern and eastern regions in the 1960s and 1970s. Cumulative losses through the peak epidemic period exceeded several hundred thousand mature American elms statewide.

The Smalley breeding program

Eugene B. Smalley (1928–2002) led an elm breeding program at the University of Wisconsin–Madison from the 1960s through the 1990s. The program emphasized hybridization between American elm and Asian species (Japanese elm, Wilson's elm, Siberian elm) to combine American elm form with Asian elm DED resistance.

Smalley's program produced or provided parental material for:

Multiple early American × Asian hybrids that informed subsequent breeding

The 'New Horizon' elm (Ulmus pumila × Ulmus davidiana hybrid)

Parental contributions to the Athena® and Allee® lines later commercialized by Earl Cully

Foundational genetic and breeding research published in Annual Review of Phytopathology and other journals

The Smalley program's emphasis on hybridization shaped the trajectory of North American elm breeding and remains a major influence on commercial cultivars.

Municipal management

Madison

The City of Madison's elm management program has operated since the 1970s with sustained municipal support. The University of Wisconsin–Madison campus also maintains active elm management. Madison retains substantial mature American elm canopy in older residential neighborhoods.

Milwaukee

Milwaukee's elm program has operated through its Department of Public Works Forestry Section. The city lost most of its peak mature elm canopy through the epidemic period but retains active management of remaining specimens and substantial replacement planting with resistant cultivars.

Smaller cities

Many smaller Wisconsin cities maintain active elm sanitation programs at the municipal level, supported by guidance from the Wisconsin Department of Natural Resources Forest Health Program and University of Wisconsin Extension.

Climate and beetle factors

Wisconsin's climate provides moderate advantages for elm management — cold winters limit beetle activity but summers are warm enough to support active beetle populations during the flight season. Beetle pressure is generally higher than in Minnesota or Manitoba but lower than in mid-Atlantic states.

Quarantine and regulations

Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) maintains state-level controls on the movement of elm wood. Firewood movement restrictions apply across the state, with particular emphasis on preventing further spread to areas with surviving mature populations.

Resistant cultivar deployment

Wisconsin municipalities and the University of Wisconsin Arboretum maintain extensive plantings of resistant cultivars for both replacement planting and ongoing performance evaluation. The state has been an early site for trials of Smalley-program-derived hybrids and subsequent USDA, Morton Arboretum, and Athens Select releases.

Related pages

Dutch Elm Disease in Minnesota — comparable upper Midwest state

Dutch Elm Disease in the United States

Athena® Elm — partly traceable to Smalley program parental material

Allee® Elm — partly traceable to Smalley program parental material

References

Smalley, E. B., & Guries, R. P. (1993). "Breeding elms for resistance to Dutch elm disease." Annual Review of Phytopathology, 31, 325–354.

Guries, R. P., & Smalley, E. B. (2000). "Once and future elms: classical and molecular approaches to Dutch elm disease resistance." In The Elms: Breeding, Conservation, and Disease Management (pp. 231–248). Kluwer Academic Publishers.

Wisconsin Department of Natural Resources. Forest health annual reports.

University of Wisconsin–Madison. Department of Plant Pathology elm research records.