Allee® Elm (Ulmus parvifolia 'Emer II')

Allee® (cultivar name 'Emer II') is a Chinese elm (Ulmus parvifolia) selection released by Athens Select. It is distinguished among Chinese elm cultivars by its strongly upright vase-shaped form, which approximates the silhouette of the classic American elm while retaining the high natural DED resistance of the parent species.

Origin

Allee® was selected from a Chinese elm specimen at the University of Georgia in Athens by Earl Cully (Heritage Trees Nursery, Petersburg, Illinois) and Michael Dirr (University of Georgia). The original tree had been growing on the University of Georgia campus for several decades. Commercial release followed in the late 1990s through Athens Select.

The cultivar's American-elm-like vase form is unusual among Chinese elm cultivars, which more commonly produce rounded or weeping forms.

Identification

Form: Strong vase shape with arching scaffold branches, broadly reminiscent of American elm but more compact

Mature size: 60–70 feet tall, 50–60 foot crown spread

Leaves: Small (1–2 inches), oval, single-serrated, dark glossy green; semi-evergreen in mild climates

Bark: Distinctive mottled exfoliating lacebark in patches of gray, green, orange, and brown

Fall color: Yellow to reddish

Growth rate: Fast in establishment, moderate at maturity

Hardiness and adaptability

USDA hardiness zones: 5–9

Site preferences: Adaptable to a wide range of soils; tolerant of urban conditions, compaction, drought, heat, and pollution

Stress tolerance: Among the most adaptable resistant elms; particularly well-suited to the southern United States

Dutch Elm Disease resistance

Allee® demonstrates high natural DED resistance characteristic of Chinese elm. The cultivar has performed strongly in regional trials and field plantings, with minimal recorded DED mortality. The Chinese elm species is also resistant to elm yellows phytoplasma.

Landscape uses

Street trees throughout the southern and central United States

Park and campus plantings

Restoration of urban canopy in DED-affected regions seeking a vase-shaped silhouette without using American elm cultivars

Specimen plantings where the mottled lacebark is featured

Limitations

Late summer to fall flowering and fruiting drop heavy seed loads in some regions, which can be a litter issue

Mature size may exceed available planting space for some street tree applications

Cold-hardiness limited to zone 5 minimum; not recommended for northern climates

Sometimes confused at nurseries with Siberian elm (U. pumila) — verify cultivar identity using the mottled exfoliating bark, which Siberian elm lacks

Similar cultivars

Athena® — companion Chinese elm release with rounded smaller form

'Drake' — Chinese elm cultivar with weeping form

Accolade™ — Japanese × Wilson's elm hybrid with upright form

Related pages

What Cultivars Are Resistant to Dutch Elm Disease?

Disease-Resistant Varieties Guide

Chinese Elm (Ulmus parvifolia)

References

Ware, G. H. (1995). "Little-known elms from China: landscape tree possibilities." Journal of Arboriculture, 21(6), 284–288.

Griffin, J. J., Jacobi, W. R., McPherson, E. G., et al. (2017). "Ten-year performance of the United States National Elm Trial." Arboriculture & Urban Forestry, 43(3), 107–120.

Santamour, F. S., & Bentz, S. E. (1995). "Updated checklist of elm (Ulmus) cultivars for use in North America." Journal of Arboriculture, 21(3), 122–131.