820 Zelkova serrataCommon Names: Japanese zelkova, sawtooth zelkova, sawleaf zelkova Family: Ulmaceae (elm Family)
Japanese zelkova is a deciduous tree that grows to 50-60 ft (15.2-18.3 m) in height and rarely will reach 100 ft (30.5 m). This attractive tree has a vase shaped form when young and a rounded umbrella-like habit when mature. Older trees grown in the open can have a very wide and majestic canopy. The bark is smooth and light gray, with prominent raised lenticels (small wartlike corky swellings that allow for the passage of oxygen and carbon dioxide). The bark peels to reveal orange patches. The leaves are alternate, somewhat rough on top, oblong-ovate, 1-2 in (2.5-5.1 cm) long but can be up to 5 in (12.7 cm) long on some fast growing shoots. They have tapering tips, prominent veins and marginal teeth. The foliage usually puts on a showy display in fall when the leaves turn yellow then orange or red before dropping. The flowers are small and insignificant. The fruits are green rounded dry nutlike drupes about 1/4 in (0.6 cm) across.
'Goblin' is a slow-growing bushy form to 3 ft (0.9 m) tall and 3 ft (0.9 m) wide. 'Green Vase' is quite vase-shaped with upright branches and fall foliage that turns bronzy red. 'Village Green' has wine colored fall foliage and is said to be more resistant to Dutch elm disease.
Zelkova serrata is native to Japan, Taiwan and southern Korea. This tree is often used in American and European landscapes.
CultureJapanese zelkova is adaptable to a wide range of site and soil conditions. It grows in alkaline to acidic soils; is wind and drought tolerant; and endures urban air pollution. It is susceptible to Dutch elm disease, but the elm bark beetle which spreads the disease rarely feeds on zelkova so infection is rare. Light: Full sun to partial shade. Moisture: Established trees are fairly drought tolerant, but the finest specimens are grown with regular watering. Hardiness: USDA Zones 5 - 9. Propagation: Zelkova can be propagated by seed sown outdoors in fall. Greenwood cuttings taken in spring or summer from young plants can be made to take root. Root suckers can be transplanted. Named selections are usually grafted or budded onto seedling stock.
Zelkova is decidedly elmlike in shape and is often used as a replacement for American elm where the latter has died out due to Dutch elm disease. This is a handsome street tree or specimen for a park or large garden. They are valued for their stately wide-spreading canopy and excellent fall color. There are smaller cultivars available for smaller gardens. Japanese zelkova is an important timber tree in Japan, where its close-grained high quality wood is used to make fine furniture. With its small leaves, pretty exfoliating gray and orange bark, and handsome fall color, Japanese zelkova is a favorite subject for bonsai.
The zelkovas are related and quite similar to the elms (genus Ulmus) but can be distinguished by their unwinged fruits and their leaves which are symmetrical rather than uneven at their bases. There are five or six species of Zelkova but this one is most common in cultivation.
Steve Christman 10/8/00; updated 1/25/04