Ulmus Commendation™

Commendation™ elm was selected for its rapid growth, robust size, cold tolerance, broad adaptability, and excellent resistance to Dutch elm disease. This tree with its symmetrical arching branches develops an attractive upright to oval habit over time. The large, dark green leaves turn yellow in autumn. It is moderately susceptible to insect problems, notably elm leaf beetle, Japanese beetle, and gypsy moth. Resulting from a controlled cross conducted by Dr. George Ware at The Morton Arboretum using Accolade™ elm (U. davidiana var. japonica) as the female parent and a hybrid elm (U. pumila × U. minor) wild-collected in Russia as the male parent.

The elm improvement program at The Morton Arboretum was initiated to address the need for an alternative to the American elm which was suffering signifi cant losses at the time due to Dutch elm disease. Hundreds of open-pollinated seedlings were examined and evaluated for Dutch elm disease-resistance, production ease, hardiness, and landscape performance in the Midwestern U.S. Commendation™ elm which is a fast-growing and robust tree with an oval habit and yellow fall color.