American Elm
Ulmus americana
Deciduous TreeAbout American Elm
The American Elm is an iconic shade tree known for its graceful, vase-shaped form. Once lining streets across the eastern United States, populations were devastated by Dutch elm disease in the mid-20th century. Disease-resistant cultivars are now available for replanting efforts.
Quick Facts
How to Identify American Elm
- Classic vase-shaped silhouette with arching branches
- Leaves are asymmetrical at the base with doubly serrated margins
- Bark is dark gray with deep, interlacing ridges
- Small, wafer-like samaras appear in spring before leaves fully emerge
- Alternate leaf arrangement along zigzag twigs
Care Guide
- Plant disease-resistant cultivars such as 'Valley Forge' or 'Princeton'
- Prune in late fall or winter to reduce spread of Dutch elm disease
- Water deeply during dry periods
- Avoid wounding bark, which attracts elm bark beetles
- Monitor for early signs of Dutch elm disease and remove infected branches immediately
Known Issues (5)
Asian Longhorned Beetle
CRITICALA large wood-boring beetle that attacks hardwoods including maples, elms, willows, and birches. Native to China and Korea, it was first detected in New York in 1996. Infestations can kill trees within a few years.
Affecting 5 regions
Dutch Elm Disease
CRITICALA devastating vascular wilt disease spread by elm bark beetles that has killed millions of American elms since the 1930s. The fungus blocks water-conducting vessels, causing rapid wilting. It fundamentally changed the American urban landscape.
Affecting 45 regions
Bacterial Leaf Scorch
HIGHA chronic bacterial disease that affects many shade tree species, particularly oaks, elms, sycamores, and maples. The bacterium is transmitted by xylem-feeding leafhoppers and spittlebugs and colonizes the water-conducting vessels, restricting water flow. Symptoms worsen each year as more of the canopy is affected. There is no cure.
Affecting 19 regions
Verticillium Wilt
HIGHA soilborne fungal disease that affects hundreds of plant species including maples, elms, redbuds, and many other trees. The fungus invades through roots and colonizes the vascular system, blocking water transport. Symptoms often appear suddenly on individual branches. Maples are particularly susceptible. Olive-green to brown streaking in the sapwood is diagnostic.
Affecting 27 regions
Leaf Spot Diseases
LOWA broad group of fungal diseases that cause discrete spots on the leaves of deciduous trees. Most are primarily cosmetic and do not seriously harm established trees. They are most common during wet spring and summer weather. Many different fungi cause leaf spots on different tree species.
Affecting 38 regions