Ulmus pumila: Siberian Elm

Introduction

This rapidly-growing deciduous tree has a rounded canopy with somewhat drooping branches, and reaches 40 to 60 feet in height with a spread of 35 to 50 feet. The glossy green, two to three-inch-long by 0.5- to 1-inch-wide leaves turn pale yellow in fall before dropping. The inconspicuous, green, springtime flowers are produced in small clusters among the leaves and are followed by half-inch-long, flat, winged seedpods which mature during early summer. The wood is fairly brittle and subject to damage during storms, which creates a lot of twig litter on the lawn afterward. Since major limbs split from the crotches on older trees, this is considered a tree to avoid. Most urban tree managers and horticulturists will not recommend planting this tree. However, recent observations showed that improper pruning, including topping, may be partially responsible for the tree's weak-wooded reputation.

General Information

Scientific name: Ulmus pumila

Pronunciation: UL-mus PEW-mih-luh

Common name(s): Siberian elm

Family: Ulmaceae

USDA hardiness zones: 5A through 9B (Fig. 2)

Origin: not native to North America

Invasive potential: little invasive potential

Uses: shade

Availability: somewhat available, may have to go out of the region to find the tree

Description

Height: 50 to 70 feet

Spread: 35 to 50 feet

Crown uniformity: irregular

Crown shape: vase

Crown density: moderate

Growth rate: fast

Texture: medium

Foliage

Leaf arrangement: alternate (Fig. 3)

Leaf type: simple

Leaf margin: serrate

Leaf shape: elliptic (oval), lanceolate

Leaf venation: pinnate

Leaf type and persistence: deciduous

Leaf blade length: less than 2 inches

Leaf color: green

Fall color: yellow

Fall characteristic: showy

Flower

Flower color: green

Flower characteristics: not showy

Fruit

Fruit shape: round

Fruit length: .5 to 1 inch

Fruit covering: dry or hard

Fruit color: brown

Fruit characteristics: does not attract wildlife; not showy; fruit/leaves a litter problem

Trunk and Branches

Trunk/bark/branches: branches droop; not showy; typically one trunk; thorns

Pruning requirement: needed for strong structure

Breakage: susceptible to breakage

Current year twig color: gray, green

Current year twig thickness: thin

Wood specific gravity: unknown

Culture

Light requirement: full sun

Soil tolerances: clay; sand; loam; alkaline; acidic; extended flooding; well-drained

Drought tolerance: high

Aerosol salt tolerance: moderate

Other

Roots: can form large surface roots

Winter interest: no

Outstanding tree: no

Ozone sensitivity: tolerant

Verticillium wilt susceptibility: susceptible

Pest resistance: sensitive to pests/diseases

Use and Management

Siberian elm grows well in full sun on well-drained soil. This tree is easily grown and will tolerate a variety of adverse conditions, such as poor soil, drought, and moderate salt. It is probably best saved for the reclamation site or other out-of-the-way location. It is also useful in climates where many other trees grow poorly. This could include the drier parts of the central United States.

Propagation is by seed or layering.

Pests

Mites and elm leaf beetles infest this elm. The tree is considered weak wooded.

Diseases

Wetwood disease can infect the trunk.