Culture
Grow in average, medium moisture, well-drained soils in full sun. Tolerant of light shade. Prefers rich, moist loams. Adapts to both wet and dry sites. Generally tolerant of urban conditions. Regular pruning and spraying is advisable.
Noteworthy Characteristics
Ulmus is a genus of about 45 species of mainly trees and a few shrubs from found in the North Temperate regions. Plants are usually deciduous but some species are semi-evergreen.
Genus name comes from the Latin name.
'New Horizon' is a compact, upright, rapid-growing, hybrid elm that typically matures over time to 40' tall and to 25' wide. It is the result of a cross between Ulmus pumila (Siberian elm) and Ulmus davidiana var. japonica (Japanese elm). It reportedly has excellent resistance to Dutch elm disease. 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. Ovate-elliptic, dark green leaves (to 4" long) have double serrate margins, acuminate tips and asymmetrical bases. Fall color is not showy. U.S. Plant Patent PP08,684 was issued on April 12, 1994.
Problems
'New Horizon' has excellent resistance to Dutch elm disease, elm leaf miner, black leaf spot and verticillium wilt. Phloem necrosis, wetwood, various wilts, rots and cankers may occur. Insect visitors may include borers, leaf miner, beetles, mealy bugs, caterpillars and scale.
Uses
May be used as a lawn, shade or street tree.