Siberian Elm (Ulmus pumila)

The Siberian elm (Ulmus pumila) is the most controversial elm in North American horticulture. It was widely planted across the Midwest and Great Plains in the early 20th century as a drought-tolerant shelterbelt tree, then proved to be weak-wooded, short-lived, and aggressively invasive. It is also persistently mislabeled as Chinese elm at retail nurseries — a confusion that continues to cause both ecological and consumer-protection problems.

Identification

Mature size: 40–70 feet tall, often with broken or storm-damaged form by mid-life.

Form: Rounded or irregular crown; trees frequently lose major branches in storms due to weak wood and included bark in branch unions.

Leaves: 1.5–3 inches long, oval, with single-serrated margins (not double-serrated like American elm). Smooth on both sides. Slightly asymmetrical base. Yellow fall color.

Bark: Gray to gray-brown, deeply furrowed with a characteristic interlocking ridge pattern. Importantly: not mottled or exfoliating — this is the easiest field distinction from true Chinese elm.

Flowers and fruit: Greenish flowers in early spring before leaf-out; produces large quantities of small, papery, single-seeded samaras in late spring. Seeds germinate readily wherever they land.

Native range and history of introduction

Native to eastern Siberia, Mongolia, Korea, and northern China. Introduced to North America in the early 1900s as a fast-growing windbreak tree for the prairies. Promoted heavily during the 1930s Dust Bowl era as part of federal shelterbelt programs (the Plains States Forestry Project planted millions). Performed well as a windbreak — drought-tolerant, fast-growing, low-maintenance.

The downsides emerged within a few decades:

Weak wood prone to breakage in wind and ice

Short useful life (40–80 years vs. 200+ for American elm)

Highly invasive — abundant seed germinates in disturbed soil, fence lines, and cracks

Aggressive root system that damages pavement and infrastructure

Hybridizes with native red elm (U. rubra), polluting native gene pools

Today, Siberian elm is considered a problematic invasive species in the central and western United States. Many state and municipal lists discourage or prohibit further planting.

Susceptibility to Dutch Elm Disease

Siberian elm is moderately resistant to DED — better than American or English elm, but more susceptible than true Chinese elm. Trees do get infected and die, especially in heavy disease-pressure areas, but losses are slow enough that the species' invasiveness has continued to outpace its decline.

The Chinese elm confusion

For decades, retail nurseries have sold Siberian elm under the name "Chinese elm." The error was once partly genuine taxonomic confusion, but it persists today as a marketing problem — buyers want the desirable Chinese elm and end up with the undesirable Siberian elm.

How to verify cultivar identity:

Feature | Chinese elm (U. parvifolia) | Siberian elm (U. pumila)
Bark on mature wood | Mottled, exfoliating in patches | Gray-brown, deeply furrowed
Leaf size | Small (1–2") | Slightly larger (1.5–3")
Flowering season | Late summer/fall | Early spring
Form | Graceful arching branches | Coarse, often broken
Latin name on tag | Ulmus parvifolia | Ulmus pumila

If a nursery tag reads Ulmus pumila — even when labeled "Chinese elm" — the tree is Siberian elm. Deliberate selection of Siberian elm for landscaping is rare in current practice.

Legitimate uses

Despite its problems, Siberian elm has limited legitimate roles:

As a parent in resistant elm breeding — its DED resistance has been combined with American elm form in cultivars like 'New Horizon' (U. pumila × U. davidiana)

In its native range in central Asia, where it is ecologically appropriate

As bonsai stock — though true Chinese elm is preferred

Management for existing trees

For a mature Siberian elm already on a property:

Don't expect long lifespan; storm damage is common

Watch for DED symptoms; fungicide treatment is rarely cost-effective for this species

Remove seedlings aggressively to limit invasive spread

Consider replacement with a true resistant elm cultivar or other species

Related pages

Elm Species: A Complete Guide

Chinese Elm (Ulmus parvifolia)

How to Identify an Elm Tree

What Cultivars Are Resistant to Dutch Elm Disease?

References

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

Czarapata, E. J. (2005). Invasive Plants of the Upper Midwest. University of Wisconsin Press.

Zalapa, J. E., Brunet, J., & Guries, R. P. (2009). "Patterns of hybridization and introgression between invasive Ulmus pumila (Ulmaceae) and native U. rubra." American Journal of Botany, 96(6), 1116–1128.