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Ulmus rubra

slippery elm

Ulmaceae Eastern and central North America

Drought Tolerant

Native to North America

SunFull Sun – Part Shade

WaterMedium · drought-tolerant

HardinessZones 3–9

Overview

Ulmus rubra is a deciduous tree growing 40-60 feet (12-18 m) tall and 30-50 feet (9-15 m) wide, with a broad, spreading to vase-shaped crown and a usually single trunk. The dark green leaves are 4-7 inches (10-18 cm) long, oval with a lopsided base and doubly toothed edges, and rough as sandpaper on the upper surface. Reddish, hairy buds and the mucilaginous, slippery inner bark, long used in folk medicine, give the tree its common names. Small reddish-green flowers open in clusters in late winter before the leaves, followed by round, flat, papery samaras that ripen in spring. In fall the foliage turns dull yellow. It is native to moist bottomlands, slopes, and stream banks across eastern and central North America, where it grows on a wide range of soils. It tolerates dry and alkaline ground better than many trees but is vulnerable to Dutch elm disease and elm leaf beetle, which limit its lifespan in some areas. The rough leaves and arching form suit large, open spaces rather than confined yards.

Native Range

Native to eastern and central North America, from southern Quebec and Maine west to the Dakotas and south to Texas and Florida. It grows in moist bottomlands, floodplains, slopes, and stream banks.

Suggested Uses

Used as a shade tree in parks, large yards, and naturalized areas, and in restoration plantings on bottomland soils. The spreading crown gives shade in open spaces with room for its width. Samaras and foliage support birds, mammals, and butterfly larvae.

How to Identify

Recognized by large oval leaves 4-7 inches (10-18 cm) long with a strongly uneven base, doubly toothed margins, and a sandpapery upper surface. The buds are reddish-brown and covered with rusty hairs, and the inner bark is mucilaginous and slippery when chewed. Flat, round, papery samaras and the rough leaves separate it from American elm, which has smoother leaves and hairless buds.

Appearance

Size & Dimensions

Height40' - 60'

Width/Spread30' - 50'

Reaches mature size in approximately 20 years

Colors

Flower Colors

red

green

Foliage Colors

green

Fall Foliage Colors

yellow

Bloom Information

Bloom Period

~2 weeks

Spring

Flowers open in late winter to early spring, often February to March, before the leaves, in small reddish-green clusters along the twigs. The flowers are wind-pollinated and inconspicuous. Flat, round samaras develop quickly and ripen and fall in spring.

Detailed Descriptions

Foliage Description

dark green, turning dull yellow in fall

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-8 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 8.0(Neutral)

357912

Soil Types

loam clay sand

Drainageaverage

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

moderate

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Grows in full sun to partial shade on moist, fertile soils but adapts to dry, clay, and alkaline ground with a pH of about 6.0-8.0. It tolerates occasional flooding and short droughts once established and needs only moderate water. It is hardy in USDA zones 3-9 across a wide climate range. Dutch elm disease and elm leaf beetle can shorten its life, so it is often planted where some loss is acceptable. It grows at a moderate rate and develops a deep, wide root system. Pruning wounds made in winter, when beetles that spread elm disease are inactive, reduce infection risk.

Pruning

Pruning is done in winter while dormant, which lowers the risk of spreading Dutch elm disease through fresh wounds. Dead, crossing, or weak branches can be removed to build a strong framework on young trees. Large cuts are avoided where disease pressure is high.

✓ Toxicity

Non-toxic