Ulmus americana ‘Valley Forge’ is a medium to large, vase-shaped, deciduous tree, typically growing to 60-80 feet (less frequently to 130 feet) tall with a broad-rounded crown. It is native to eastern and central North America. Although once widely planted in the United States as street and lawn trees, American elms have now been so decimated by Dutch elm disease that species trees are no longer considered to be viable selections for landscapes. Ulmus americana ‘Valley Forge’ reportedly has excellent resistance to Dutch elm disease and is currently being planted. It typically grows to 60-70 feet tall. Non-showy, small green flowers appear in spring before the foliage emerges. Flowers give way to single-seeded, wafer-like samaras (each tiny seed is surrounded by a flattened oval-rounded papery wing). Seeds mature in April-May as the leaves reach full size. Rough-textured, ovate-elliptic, dark green leaves (to 6 inches long) have toothed margins and asymetrical bases. Leaves typically turn yellow in fall. 'Valley Forge' has excellent resistance to Dutch elm disease. It is susceptible to phloem necrosis that is a viral disease that attacks the food-conducting tissue of the tree, usually resulting in a loosening of the bark, wilting, defoliation and death. It is also susceptible to wetwood that is a 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 scale.