Japanese Zelkova

a BEAUTIFUL & TOUGH CITY TREE

Japanese zelkovas in November don the autumnal dress.

An immature zelkova in the summer.

Specimen shade tree-Zelkova

Kidney shaped seed pods form in leaf axils.

A sample of Zelkova's jewel toned fall leaves.

City planted Zelkovas cover the street with their golden confetti.

A curtain of vibrant Zelkova fall foliage.

A zelkova in October changing into its autumnal dress.

Zelkovas have good branching structure so they look good all year.

Full sun is needed for good fall colour.

Common Name: Japanese Zelkova
Botanical Name: Zelkova serrata
Form: vase shaped canopy
Family: Ulmaceae
Genus: Zelkova
Species: serrata
Plant Type: deciduous tree
Mature Size: 50 to 80 feet (15 to 24m) tall and wide
Growth: moderate to fast
Origin: Japan, Korea, eastern China and Taiwan
Hardiness Zone: 5 to 8
Foliage: simple, alternate, elliptic, oblong, green, to 3” long, sharply serrated margins with pointed tips, brilliant fall colour
Flowers: small, green, insignificant, March, April as leaves emerge
Fruit: small, wingless kidney shaped drupes
Bark: smooth, grey when immature, exfoliates when mature revealing orange inner bark
Exposure: sun
Soil: soil tolerant, prefers moist, well-drained, mulch to conserve moisture
Uses: shade tree, street tree, specimen, winter interest, autumn colour, bonsai, elm tree substitute
Attracts: bird habitat and nesting, pollinators
Invasive Tendencies: no
Tolerates: drought, pollution, urban conditions and compacted soil, high winds
Awards: received Royal Horticultural Society Award of Garden Merit
Propagation: seeds, softwood cuttings in early summer
Pruning: late winter to remove dead, crossing branches
Problems: no serious insects or diseases, resistant to Dutch elm disease
Comments:
The Japanese zelkova is a beautiful tree with attributes suitable for urban and suburban landscapes. This durable, long-lived tree features a sturdy, short trunk that withstands strong winds. Drought tolerant once it’s established, it is also adaptable to different soil conditions. Pollution tolerant, zelkovas are used as street trees in cities and urban areas.
The Japanese zelkova is a moderately large ornamental deciduous tree. Its wide, rounded vase shaped canopy makes it a suitable shade tree. Branches form low on its short stocky trunk. It’s smooth and grey when young, but as it matures, the outer bark peels away to reveal an orange inner bark.
Their deeply veined, feather shaped leaves are sharply serrated. In autumn their bright green foliage changes into brilliant hues of yellow, orange and red. Inconspicuous green flowers appear just as the foliage emerges in spring. The blossoms are followed by small triangular, kidney-shaped drupe that ripen in early fall.
To get the best fall colour and a happy tree, plant zelkovas in full sun. Although they are soil tolerant, they prefer moist, well drained soil. A thick layer of mulch is beneficial to retain soil moisture and to add nutrients. Keep it a few inches away from the trunk to prevent it from rotting. Do not rake their foliage away in fall as it provides nutrients and winter protection for the tree.
Pruning is generally not necessary as zelkovas have good form and are well-shaped. Do remove dead, dying, crossing and weak branches.
Prune in late winter while still dormant. Never ever remove the tree’s canopy and don’t cut all the branches back, or off. This is referred to as ‘topping’ and results in unattractive suckers instead of branches. The beautiful natural shape of the tree is lost, and it becomes unsafe as the weak suckers replace the sturdy branches. Before doing any pruning, be aware that birds love to hide and nest their sturdy branches, so inspect the tree first beforehand.