Once a very popular and long-lived (300+ years) shade and street tree, American Elm suffered a dramatic decline in the 1950's with the infestation of Dutch elm disease, a fungus spread by a bark beetle. Accolade, Commendation, Triumph, and numerous other elm varieties are the result of efforts to provide elms with more disease and insect resistance.

Cultivar 'Morton Stalwart', trade name Commendation™, is a complex hybrid of the Morton Accolade™ (fig 2.) elm and
Ulmus pumilla x U. carpinifolia (fig.1) from eastern Russia. Listed as a fast-growing, tough, robust tree, this elm grows to 60 feet and spreads to 50. Extremely drought-resistant, cold tolerant, and resistant to Dutch Elm disease, it is nevertheless moderately susceptible to gypsy moth, Japanese beetle, and elm leaf beetle damage. [1]

Chicagoland Grows™ is a corporate partnership among the Chicago Botanic Garden, the Morton Arboretum and the Ornamental Grower’s Association of Northern Illinois (OGA). Established in 1986, CG works collectively with industry professionals in the OGA and throughout North America to develop, select, evaluate, produce and market new and recommended plant cultivars. These selected plants offer fine ornamental attributes and proven dependability to both landscape professionals and home gardeners.

Family Ulmaceae - Zelkovas, Hackberries and Elms
There are about 200 species of trees and shrubs in Ulmaceae. 14 trees and 2 shrubs are native to North America. Elms fell victim to Dutch Elm disease during the 1950's; until that time, they were the premier shade tree along the streets of our American towns and cities. The Morton Arboretum in past years has bred and marketed five new elm varieties resistant to Dutch elm disease.
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