Ulmus americana, or American Elm, is a deciduous tree, that can grow to 80 to 100 feet tall with a trunk diameter of 2 to 5 feet. Older trees sometimes develop buttresses that expand their base. In nature. it can be found in swamps, bottomland forests, moist slopes, and in areas with especially nutrient-rich soils. The American elm is a beautiful shade tree with an urn shape typical of elms and a fibrous root system that makes it easy to transplant. It is susceptible to Dutch Elm disease, which makes it less than ideal for a landscape selection; however, resistant cultivars are available and are currently being evaluated.
American Elm grows well in average, medium moisture, well-drained soils in full sun, although it tolerates light shade. It prefers rich, moist loams and adapts to both wet and dry sites. It tolerates urban conditions. The leaves are alternate with a doubly toothed margin and unequal base. The bark is ashy gray with flat-topped ridges separated by diamond-shaped fissures. In late winter, small flowers mature in clusters of 3 to 5. The tree produces a flattened samara with a hairy margin. The tree often is found growing in rich soils. When sited in a dense forest, the tree tends to have a narrow crown and a long, clear bole. When sited in an open area, the tree tends to fork near the ground and develop an arching crown. Ulmus americana can be pruned and kept at shrub size by cutting them to the ground in the fall every 2 to 3 years.
Insects, Diseases, or Other Plant Problems:  
Dutch elm disease, a fatal fungal disease spread by airborne bark beetles that attacks the water-conducting tissue of the tree, resulting in wilting, defoliation and death. There is no known cure. Phloem necrosis, disease caused by a phytoplasma that attacks the food-conducting tissue of this tree, usually resulting in a loosening of the bark, wilting, defoliation and death. Wetwood, bacterial disease that results in wilting and dieback. Various wilts, rots, cankers and leaf spots may also occur. Insect visitors include borers, leaf miner, beetles, mealy bugs, caterpillars and scaleis.