Zelkova spp.

East Asia, with outlying species in the Caucasus and Mediterranean

SunFull Sun – Part Shade

HardinessZones 5–8

Overview

Zelkova spp. is a small genus of about six deciduous trees in the elm family, native to East Asia with relict species in the Caucasus and Mediterranean. The species most often grown, Z. serrata, is used as a street and shade tree in regions where Dutch elm disease has thinned American elms. Trees develop a short trunk and a spreading, vase-shaped crown, typically reaching 50 to 80 ft (15 to 24 m) tall with a comparable spread. The smooth gray bark flakes with age to expose orange-brown patches. Leaves are alternate, ovate, and sharply serrate, 2 to 5 inches (5 to 13 cm) long, dark green in summer and turning yellow, orange, to red-brown in autumn. Small green flowers open with the leaves in spring and are wind-pollinated, followed by tiny, dry, single-seeded drupes. Zelkova spp. resists Dutch elm disease far better than true elms but is not immune to elm leaf beetle, Japanese beetle, or canker, and large specimens develop surface roots that can lift pavement. Its eventual size makes it suited to parks, wide verges, and large gardens rather than confined spaces.

Native Range

Zelkova spp. is native mainly to East Asia, including Japan, Korea, China, and Taiwan, where the trees grow in mixed forests and along valleys. Three relict species survive in small areas farther west: Z. carpinifolia in the Caucasus, Z. sicula in Sicily, and Z. abelicea in the mountains of Crete.

Suggested Uses

Zelkova spp. is planted as a street, lawn, and shade tree, and as a windbreak in parks and large gardens. Z. serrata and its cultivars are also trained as bonsai for their dense, twiggy branch structure. The mature size and surface roots make it less suited to small yards and narrow planting strips.

How to Identify

Recognize Zelkova spp. by its upswept, vase-shaped crown and smooth gray bark that flakes on older trees to reveal orange inner bark. The leaves are simple, alternate, and evenly saw-toothed along the margin, with a long tapered tip, and the leaf base is nearly symmetrical, unlike the lopsided base of true elm leaves. Twigs bear small, rounded green flowers in spring and inconspicuous dry fruits.

Appearance

Size & Dimensions

Height50' - 80'

Width/Spread50' - 75'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~2 weeks

Spring

Flowers open in spring as the leaves expand, usually April to May. They are small, green, and without petals, pollinated by wind rather than insects, so they go largely unnoticed. Tiny one-seeded fruits ripen by late summer and drop with the leaves.

Detailed Descriptions

Flower Description

Greenish, inconspicuous

Foliage Description

Dark green, turning yellow to orange-red in fall

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 6-10 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 Range5.5 - 7.5(Neutral)

357912

Soil Types

clay loam sand

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

20-30 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Zelkova spp. grows in full sun on deep, moist, well-drained soil across a pH range of about 5.5 to 7.5 and adapts to clay, loam, and sandy ground. Young trees benefit from regular water, while established trees tolerate drought, heat, wind, and urban conditions. The genus is hardy in zones 5 to 8 and needs no winter protection within that range. A single, well-spaced leader is encouraged when young to avoid weak, included bark in the vase-shaped crown. Pests are usually minor but can include elm leaf beetle and Japanese beetle, and surface roots may develop on older trees.

Pruning

Pruning is done in late winter to remove crossing or crowded branches and to establish a strong central leader on young trees. Mature Zelkova spp. needs little pruning beyond removal of dead or damaged wood. Cuts heal well when kept to smaller branches.